Abstract: An FET (field effect transistor) having source, drain and channel regions of a conductivity type in a semiconductor body of opposite conductivity type. The channel region is located at the lower extremity of the source and drain regions so as to be spaced from the surface of the semiconductor body by a distance d.

Abstract: A silicon on insulator (SOI) device and methods for fabricating such a device are provided. The device includes an MOS capacitor coupled between voltage busses and formed in a monocrystalline semiconductor layer overlying an insulator layer and a semiconductor substrate. The device includes at least one electrical discharge path for discharging potentially harmful charge build up on the MOS capacitor. The MOS capacitor has a conductive electrode material forming a first plate of the MOS capacitor and an impurity doped region in the monocrystalline silicon layer beneath the conductive electrode material forming a second plate. A first voltage bus is coupled to the first plate of the capacitor and to an electrical discharge path through a diode formed in the semiconductor substrate and a second voltage bus is coupled to the second plate of the capacitor.

Abstract: Semiconductor devices can be fabricated using conventional designs and process but including specialized structures to reduce or eliminate detrimental effects caused by various forms of radiation. Such semiconductor devices can include the one or more parasitic isolation devices and/or buried guard ring structures disclosed in the present application. The introduction of design and/or process steps to accommodate these novel structures is compatible with conventional CMOS fabrication processes, and can therefore be accomplished at relatively low cost and with relative simplicity.

Abstract: A semiconductor device, including: a semiconductor substrate of a first conduction type; an active region used as a function-element-forming region on the semiconductor substrate; a low-resistance region of a second conduction type formed on an outermost periphery of the active region to surround the active region and having contact with the semiconductor substrate, the second conduction type being different from the first conduction type; and an electrode connected to the function element and the low-resistance region. A diode is formed by the semiconductor substrate and the low-resistance region. The function element and the diode are electrically connected in parallel between the semiconductor substrate and the electrode, and, between the semiconductor substrate and the electrode, resistance of the low-resistance region is lower than resistance of an electrical conduction path via the function element.

Abstract: An integrated circuit having devices fabricated in both SOI regions and bulk regions, wherein the regions are connected by a trench filled with epitaxially deposited material. The filled trench provides a continuous semiconductor surface joining the SOI and bulk regions. The SOI and bulk regions may have the same or different crystal orientations. The present integrated circuit is made by forming a substrate with SOI and bulk regions separated by an embedded sidewall spacer (made of dielectric). The sidewall spacer is etched, forming a trench that is subsequently filled with epitaxial material. After planarizing, the substrate has SOI and bulk regions with a continuous semiconductor surface. A butted P-N junction and silicide layer can provide electrical connection between the SOI and bulk regions.

Abstract: A semiconductor device, including: a semiconductor substrate of a first conduction type; an active region used as a function-element-forming region on the semiconductor substrate; a low-resistance region of a second conduction type formed on an outermost periphery of the active region to surround the active region and having contact with the semiconductor substrate, the second conduction type being different from the first conduction type; and an electrode connected to the function element and the low-resistance region. A diode is formed by the semiconductor substrate and the low-resistance region. The function element and the diode are electrically connected in parallel between the semiconductor substrate and the electrode, and, between the semiconductor substrate and the electrode, resistance of the low-resistance region is lower than resistance of an electrical conduction path via the function element.

Abstract: A high density read-only memory (ROM) cell is installed on a silicon substrate for storing data. The ROM cell includes a first doped region being of a second conductive type installed on the silicon substrate, a plurality of first heavily doped regions being of a first conductive type installed in the first doped region, a second doped region being of the second conductive type installed on the silicon substrate, and a gate installed on the surface of the silicon substrate and adjacent to the first doped region and the second doped region.

Abstract: A semiconductor device and a method of fabricating the same suppress a substrate floating effect without causing lowering of a degree of integration. The semiconductor device has a Silicon-On-Insulator structure which includes a semiconductor layer formed on an insulator, and has at least one MOSFET element. The MOSFET element includes a source region; a drain region which is opposed to the source region; a body region disposed between the source and drain regions; a gate region positioned on or close to a surface of the body region, so as to form an electrically conducting channel in the body region; and an extracting region being in contact with both of the body region and the source region. The extracting region has a conductivity type which is the same as a conductivity type of the body region and has a concentration higher than that of the body region.

Abstract: A MOS field effect transistor includes an auxiliary diffusion formed in the drain region where the auxiliary diffusion has a conductivity type opposite to the drain region and is electrically shorted to the drain region. The auxiliary diffusion region forms a parasitic bipolar transistor having the effect of reducing substrate conduction caused by a forward biased drain to body junction.

Abstract: Layout patterns for the deep well region to facilitate routing the body-bias voltage in a semiconductor device are provided and described. The layout patterns include a diagonal sub-surface mesh structure, an axial sub-surface mesh structure, a diagonal sub-surface strip structure, and an axial sub-surface strip structure. A particular layout pattern is selected for an area of the semiconductor device according to several factors.

Abstract: A double-triggered silicon controller rectifier (SCR) comprises a plurality of N+ diffusion areas, a plurality of P+ diffusion areas, a first N-well region, a second N-well region and a third N-well region formed in a P-substrate. The N+ diffusion areas and the P+ diffusion areas are isolated by shallow trench isolation (STI) structures. Two of the N+ diffusion areas are N-type trigger terminals. Two of the P+ diffusion areas are the P-type trigger terminal.

Abstract: The present invention is related to an Electrostatic Discharge protection device. This may be a semiconductor device such as a CMOS transistor, having a snap-back IV characteristic, in order to withstand ESD pulses. The device of the invention comprises an additional doped region, which influences the internal resistance of the substrate whereupon the device is built. This has a positive effect on the snap-back characteristic, putting the snap back trigger voltage and current at a lower value, compared to prior art devices.

Abstract: An aspect of the present invention provides a semiconductor device includes that a drain region of a first conductivity type formed in a semiconductor substrate, a source region of the first conductivity type, an insulating film in contact with the source region, a gate electrode insulated from the source region by the insulating film, and a base region of a second conductivity type electrically connected to the gate electrode and in contact with the drain region, wherein majority carriers flow between the source region and the drain region before minority carriers are introduced from the base region into the drain region when a predetermined potential is applied to the gate electrode.

Abstract: Briefly, in accordance with one embodiment of the invention, an integrated circuit has a voltage generator that selectively increases the voltage potential on the channel region of a transistor relative to the source region of the transistor. The voltage potential may be provided to a diffusion region in the well regions with transistors.

Abstract: A MIS type semiconductor device and a method for fabricating the same characterized in that impurity regions are selectively formed on a semiconductor substrate or semiconductor thin film and are activated by radiating laser beams or a strong light equivalent thereto from above so that the laser beams or the equivalent strong light are radiated onto the impurity regions and on an boundary between the impurity region and an active region adjoining the impurity region.

Abstract: Complementary metal-oxide-semiconductor (CMOS) integrated circuits with bipolar transistors and methods for fabrication are provided. A bipolar transistor may have a lightly-doped base region. To reduce the resistance associated with making electrical contact to the lightly-doped base region, a low-resistance current path into the base region may be provided. The low-resistance current path may be provided by a base conductor formed from heavily-doped epitaxial crystalline semiconductor. Metal-oxide-semiconductor (MOS) transistors with narrow gates may be formed on the same substrate as bipolar transistors. The MOS gates may be formed using a self-aligned process in which a patterned gate conductor layer serves as both an implantation mask and as a gate conductor. A base masking layer that is separate from the patterned gate conductor layer may be used as an implantation mask for defining the lightly-doped base region.

Abstract: Diagonal deep well region for routing the body-bias voltage for MOSFETS in surface well regions is provided and described.

Abstract: A semiconductor device for a charge pump device suitable for providing large current capacity and preventing a latch up from occurring is offered. A first and a second N-type epitaxial silicon layers are stacked on a P-type single crystalline silicon substrate, and P-type well regions are formed in the second epitaxial silicon layer. P+-type buried layers abutting on bottoms of the P-type well regions and N+-type buried layers abutting on bottoms of the P+-type buried layers and electrically isolating the P-type well regions from the single crystalline silicon substrate are formed. An MOS transistor is formed in each of the P-type well regions and a drain layer of the MOS transistor and each of the P-type well regions are electrically connected.

Abstract: A semiconductor arrangement including: a substrate having a substrate layer (13) with an upper and lower surface, the substrate layer (13) being of a first conductivity type; a first buried layer (12) in the substrate, extending along said lower surface below a first portion of said upper surface of said substrate layer (13), and a second buried layer (12) in the substrate, extending along said lower surface below a second portion of said upper surface of said substrate layer (13); a first diffusion (26) in said first portion of said substrate layer (13), being of a second conductivity type opposite to said first conductivity type and having a first distance to said first buried layer (12) for defining a first breakdown voltage between said first diffusion (26) and said first buried layer (12); a second diffusion (45) in said second portion of said substrate layer (13), being of said second conductivity type and having a second distance to said second buried layer (12) for defining a second breakdown volta

Abstract: In a charge pump device, occurrence of a latch up can be prevented and current capacity can be increased. An N-type epitaxial silicon layer is formed on a P-type single crystalline silicon substrate, P-type well regions are formed in the N-type epitaxial silicon layer separated from each other, and P-type lower isolation layers and P-type upper isolation layers are formed between the P-type well regions. Then a charge transfer MOS transistor is formed in each of the P-type well regions. The P-type single crystalline silicon substrate is biased to a ground potential or a negative potential.

Abstract: The present invention is directed to a seal structure and a method for forming a seal structure for a semiconductor die. An elongate region which is electrically isolated from the remainder of the substrate, such as a well region of a conductivity type opposite that of the substrate, extends around the major portion of the periphery of the substrate. A gap is left between the two ends of the elongate region along the minor portion of the periphery of the substrate not covered by the elongate region. A conductive seal ring is formed around the periphery of the substrate at the elongate region and spans the gap between the ends of the elongate region. The substrate of the semiconductor die is only brought into electrical contact with the seal ring at the gap between the ends of the elongate region.

Abstract: A semiconductor device for a charge pump device suitable for providing large current capacity and preventing a latch up from occurring is offered. A first and a second N-type epitaxial silicon layers are stacked on a P-type single crystalline silicon substrate, and a P-type well region is formed in the second epitaxial silicon layer. A P+-type buried layer is formed abutting on a bottom of the P-type well region, and an MOS transistor is formed in the P-type well region. The MOS transistor has a first source layer N+S of high impurity concentration, a first drain layer N+D of high impurity concentration and a second source layer N?S and/or a second drain layer N?D of low impurity concentration, which is diffused deeper than the first source layer N+S of high impurity concentration and the first drain layer N+D of high impurity concentration.

Abstract: A latch up in a charge pump device is prevented as well as a withstand voltage of an MOS transistor used in the charge pump device is increased with this invention. A first and a second N-type epitaxial silicon layers are stacked on a P-type single crystalline silicon substrate, and P-type well regions are formed in the second epitaxial silicon layer separated from each other. A P-type isolation layer is formed between the P-type well regions. A P+-type buried layer is formed abutting on a bottom of each of the well regions, an N+-type buried layer is formed abutting on a bottom of the P+-type buried layer, and a transistor for charge transfer is formed in each of the P-type well regions.

Abstract: A semiconductor device for a charge pump device suitable for providing large current capacity and preventing a latch up from occurring is offered. An N-type epitaxial silicon layer is formed on a P-type single crystalline silicon substrate, and a P-type well region is formed in the N-type epitaxial silicon layer. A P+-type buried layer abutting on a bottom of the P-type well region and an N+-type buried layer partially overlapping with the P+-type buried layer and electrically isolating the P-type well region from the single crystalline silicon substrate are formed. And then, an MOS transistor is formed in the P-type well region.

Abstract: A semiconductor device is provided with a memory cell. The semiconductor device includes a first gate-gate electrode layer, a second gate-gate electrode layer, a first drain-drain wiring layer, a second drain-drain wiring layer, a first drain-gate wiring layer and a second drain-gate wiring layer. The first drain-gate wiring layer and an upper layer and a lower layer of the second drain-gate wiring layer are located in different layers, respectively.

Abstract: An integrated circuit including a vertical power component having a terminal formed by a chip substrate of a first conductivity type, a control circuit thereof, the control circuit isolated from the substrate by an isolation region of a second conductivity type, and a protection structure against polarity inversion of a substrate potential. The protection structure includes a first bipolar transistor with an emitter connected to said isolation region and a collector connected to a reference potential input of the integrated circuit, a bias circuit for biasing the first bipolar transistor in a reverse saturated mode when the substrate potential is higher than the reference potential, and a second bipolar transistor with an emitter connected to the substrate and a base coupled to the isolation region for coupling the isolation region to the substrate through a high-impedance when the substrate potential is lower than the reference potential.

Abstract: A semiconductor device is provided which avoids lowering of the sense speeds of plural sense amplifiers due to their drives. In the semiconductor device, a P-type well layer (6) containing a P-type impurity is selectively disposed in a main surface of an epitaxial layer (3). An N-type bottom layer (7) containing an N-type impurity is disposed so as to make contact with a bottom surface of the P-type well layer (6). A P-type well layer (2) is disposed in such a thickness as to make contact with the N-type bottom layer (7), so that the N-type bottom layer (7) and P-type well layer (2) form a PN junction. Further, in the main surface of the epitaxial layer (3), an N-type well layer (4) containing an N-type impurity and a P-type well layer (5) containing a P-type impurity are selectively disposed so as to sandwich therebetween the P-type well layer (6).

Abstract: Briefly, in accordance with one embodiment of the invention, an integrated circuit has a voltage generator that selectively increases the voltage potential on the channel region of a transistor relative to the source region of the transistor. The voltage potential may be provided to a diffusion region in the well regions with transistors.

Abstract: A silicon controlled rectifier electrostatic discharge protection circuit with external on-chip triggering and compact internal dimensions for fast triggering. The ESD protection circuit includes a silicon controlled rectifier (SCR) having an anode coupled to the protected circuitry and a cathode coupled to ground, where the cathode has at least one high-doped region. At least one trigger-tap is disposed proximate to the at least one high-doped region and an external on-chip triggering device is coupled to the trigger-tap and the protected circuitry.

Abstract: A structure protects CMOS logic from substrate minority carrier injection caused by the inductive switching of a power device. A single Integrated Circuit (IC) supports one or more power MOSFETs and one or more arrays of CMOS logic. A highly doped ring is formed between the drain of the power MOSFET and the CMOS logic array to provide a low resistance path to ground for the injected minority carriers. Under the CMOS logic is a highly doped buried layer to form a region of high recombination for the injected minority carriers. One or more CMOS devices are formed above the buried layer. The substrate is a resistive and the injected current is attenuated. The well in which the CMOS devices rest forms a low resistance ground plane for the injected minority carriers.

Abstract: Isolation regions, a peripheral anode, an N-type island region for output and a passive N-type island region are formed at the main surface of a P− substrate. A dummy N-type island region is formed at a region located between two isolation regions. A P-type region is formed at the surface of this N well. A pair of N++ type regions are formed at the surface of P-type region. A gate electrode is formed on a portion of P-type region interposed between N++ type regions. N++ type region is connected to ground while N++ type region is electrically connected to isolation region. Accordingly, current is restricted from flowing between the N-type island region for output and the passive N-type island region so as to obtain a semiconductor device in which occurrence of malfunctions is prevented.

Abstract: An integrated circuit having structure for isolating circuit sections having at least one differing characteristic. The structure includes a chip guard ring for each circuit section having the at least one differing characteristic. Providing multiple chip guard rings allows for isolation of circuit sections and prevention of ionic contamination, but without increased expense and size. In addition, it is practicable with any IC. The invention also may include an interconnect for electrical connectivity about a chip guard ring.

Abstract: A process for forming at least one interface region between two regions of semiconductor material. At least one region of dielectric material comprising nitrogen is formed in the vicinity of at least a portion of a boundary between the two regions of semiconductor material, thereby controlling electrical resistance at the interface.

Abstract: A plurality of p-wells and n-wells are formed in a front side of a bulk material, and a plurality of n layers and p layers are alternately formed within the bulk material between a back side of the bulk material and the plurality of n-wells and p-wells. The plurality of n layers are electrically isolated from one another and respectively route different potentials to selected ones of the plurality of n-wells, and likewise, the plurality of p layers are electrically isolated from one another and respectively route different potentials to selected ones of the plurality of p-wells.

Abstract: A layout method is provided for a latch-up prevention circuit of a semiconductor memory device which includes the steps of: arranging a cell array at substantially the middle of the device; placing peripheral circuits next to both sides of the cell array; placing a plurality of pads on both sides of the cell array between the peripheral circuits and both edges of the device; and arranging guard rings beneath the plurality of pads. The layout method further includes a plurality of ESD protection transistors disposed axially along the direction as the plurality of pads between the plurality of pads and an edge of the device. And each of guard ring is a NWELL guard ring, and connected to a supply voltage and ground.

Abstract: A vertical bipolar transistor is described which utilizes ion implantation steps which are used to form an nMOS field effect device and a pMOS field effect device. The implantation steps form an n-well, a p-well region, a pocket base region and an emitter region which are vertically oriented within a semiconductor substrate. The resulting bipolar device may have a significant relative gain and is constructed with no additional mask steps.

Abstract: To present a SOI type MOS element excellent in yield, performance and characteristic, easy in manufacture, and low in cost, and a method of manufacturing the same. A SOI type MOS transistor structure comprising polysilicon electrodes 128 for gate, source and drain composed by burying into trench holes 120a, 120b, 120c respectively formed in a semiconductor substrate 110, a gate oxide film 122 formed in the entire inside of the trench hole 120a, N− diffusion layer 124 and N+ diffusion layer 126 formed in the entire inside of the trench holes 120b and 120c, and a thick SiO2 film 114 in a trench hole 113 formed in the semiconductor substrate 110 so as to surround the transistor.

Abstract: An integrated CMOS semiconductor circuit comprises: an internal circuit composed of CMOS transistors including P3- and N-channel transistors each having a gate electrode and source/drain regions formed on a semiconductor substrate, the internal circuit functioning in at least two states including an active state in which data is input and output, and a standby state in which a state of the internal circuit is maintained; an external circuit composed of any electrical element and provided with a power source; and a switch portion which is enable to apply, in the standby state in the internal circuit, a reverse bias between the source and the substrate of either one of the P- and N-channel transistors of the internal circuit by the power source of the external circuit.

Abstract: The present invention creates a useful BJT by increasing the gain associated with the parasitic BJT on an SOI or bulk type MOSFET. This is done by masking those manufacturing steps that minimize the BJT's beta value, by intentionally increasing the beta value of the BJT, and by driving the base of the BJT with the circuit. Once the gain is increased sufficiently, the BJT may be used productively in the circuit. Because the physical structure of the BJT is already part of the silicon water, its productive use does not require additional space.

Abstract: An N type buried layer is formed, in one embodiment, by a non selective implant on the surface of a wafer and later diffusion. Subsequently, the wafer is masked and a selective P type buried layer is formed by implant and diffusion. The coefficient of diffusion of the P type buried layer dopant is greater than the N type buried layer dopant so that connections can be made to the P type buried layer by P wells which have a lower dopant concentration than the N buried layer.

Abstract: Isolation regions, a peripheral anode, an N-type island region for output and a passive N-type island region are formed at the main surface of a P− substrate. A dummy N-type island region is formed at a region located between two isolation regions. A P-type region is formed at the surface of this N well. A pair of N++ type regions are formed at the surface of P-type region. A gate electrode is formed on a portion of P-type region interposed between N++ type regions. N++ type region is connected to ground while N++ type region is electrically connected to isolation region. Accordingly, current is restricted from flowing between the N-type island region for output and the passive N-type island region so as to obtain a semiconductor device in which occurrence of malfunctions is prevented.

Abstract: A CMOS SRAM cell with prescribed power-on data state having first and second cross-coupled inverters each defined by serially connected complementary MOS transistors (T1/T2; T3/T4) serially connected between Vdd and circuit ground to form a first inverter with a first data node (A) between the two transistors (T1/T2) of the first inverter, and, in a similar manner, to form a second inverter with a second data node (B) between the two transistors (T3/T4) of the second inverter. The gates of transistors of each inverter are connected together and cross-coupled to the data node of the other inverter. An access transistor (T5) is connected between a bit line (BL) and the first data node (A) and another access transistor (T6) is connected between a complementary bit line (BLC) and the second data node (B) to provide data access thereto.

Abstract: A silicon-on-insulator (SOI) integrated, circuit is provided. A plurality of transistor active regions and at least one body contact active region are formed on an SOI substrate. A semiconductor residue layer, which is thinner than the transistor active regions and the body contact active region, is disposed between the transistor active regions and the body contact active region. The transistor active regions, the body contact active region and the semiconductor residue layer are disposed on a buried insulating layer of the SOI substrate. The semiconductor residue layer is covered with a partial trench isolation layer. A bar-shaped full trench isolation layer is interposed between the adjacent transistor active regions. The full trench isolation layer is in contact with sidewalls of the transistor active regions adjacent thereto and is in contact with the buried insulating layer between the adjacent transistor active regions. An insulated gate pattern crosses over the respective transistor active regions.

Abstract: An insulated gate N-channel field effect transistor has a P-type semiconductor substrate, an N-type epitaxial layer disposed on the P-type semiconductor substrate, and a gate insulating film disposed on the N-type epitaxial layer. An N-type high concentration source region is formed in the N-type epitaxial layer. An N-type high concentration drain region is formed in the epitaxial layer in spaced-apart relation to the N-type high concentration source region. A channel forming region is disposed between the N-type high concentration source region and the N-type high concentration drain region. A gate electrode is formed on the channel forming region through the gate insulating film. An N-type low concentration region is disposed between the N-type high concentration drain region and the channel forming region and between the N-type high concentration source region and the channel forming region. An insulating film is disposed on the low concentration region.

Abstract: An etching mask having high etching selectivity for an inorganic interlayer film of SiO2 or Si3N4, an organic interlayer film such as ARC and an electrically conductive film and a contact hole using such an etching mask, a process for forming same and a resultant semiconductor device. On formation of contact holes for connecting wirings disposed through interlayer films of inorganic or organic material (20, 23 in FIG. 2), a thin film of silicon carbide (21 in FIG. 2) having high etching selectivity for any of the inorganic and organic materials is deposited on an interlayer film, and a mask pattern of silicon carbide is formed using a resist pattern (22 in FIG. 2). Thereafter, high aspect ratio contact holes having a size which is exactly same as that of the mask is formed by etching the interlayer film using the silicon carbide mask.

Abstract: A merged device is that comprises a plurality of MOSFET cells and a plurality of Schottky rectifier cells, as well as a method of designing and making the same. According to an embodiment of the invention, the MOSFET cells comprise: (a) a source region of first conductivity type formed within an upper portion of a semiconductor region, (b) a body region of second conductivity type formed within a middle portion of the semiconductor region, (c) a drain region of first conductivity type formed within a lower portion of the semiconductor region, and (d) a gate region provided adjacent the source region, the body region, and the drain region. The Schottky diode cells in this embodiment are disposed within a trench network and comprise a conductor portion in Schottky rectifying contact with the lower portion of the semiconductor region. At least one MOSFET cell gate region is positioned along a sidewall of the trench network and adjacent at least one Schottky diode cell in this embodiment.

Abstract: A MOS gate and associated source/drain region structure providing three junction diodes between a source/drain contact area and the substrate, instead of the typical total of one, resulting in improved isolation of a source/drain contact area and a storage node which may be formed thereat. For fabricate the structure, a source/drain region is formed in a substrate having a space charge in the bulk or major part thereof, the source/drain region including: a first region having a space charge with a charge opposite that of a space charge in the major part of the substrate; a second region separated from the major part of the substrate by the first region and having a space charge with a charge opposite that of the space charge of the first region; and a third region separated from the first region and the major part of the substrate by the second region and having a space charge with a charge opposite that of the space charge of the second region.

Abstract: A transistor on an SOI wafer has a subsurface recombination area at least partially within its body. The recombination area includes one or more damaged recombination regions. The damaged recombination region(s) may be formed by a damaging implant into a surface semiconductor layer, for example through an open portion of a doping mask, the opening portion created for example by removal of a dummy gate. Alignment of the damaged recombination region(s) is improved by forming the source and drain of the transistor prior to removal of the dummy gate, using the dummy gate as a doping mask.

Abstract: A semiconductor device improved to suppress a leakage current of a transistor is provided. A gate electrode is disposed on a semiconductor substrate. A pair of p type source/drain layers are provided on the surface of the semiconductor substrate, on both sides of the gate electrode in the gate length direction Y. An n type gate width determining layer is provided on the surface of the semiconductor substrate to sandwich the source/drain layers in the width direction X of the gate electrode, which determines a gate width of the gate electrode. The source/drain layers and the gate width determining layer are isolated by PN junction.

Abstract: To present a SOI type MOS element excellent in yield, performance and characteristic, easy in manufacture, and low in cost, and a method of manufacturing the same. A SOI type MOS transistor structure comprising polysilicon electrodes 128 for gate, source and drain composed by burying into trench holes 120a, 120b, 120c respectively formed in a semiconductor substrate 110, a gate oxide film 122 formed in the entire inside of the trench hole 120a, N-diffusion layer 124 and N+ diffusion layer 126 formed in the entire inside of the trench holes 120b and 120c, and a thick SiO2 film 114 in a trench hole 113 formed in the semiconductor substrate 110 so as to surround the transistor.