Abstract: A method for manufacturing a semiconductor device including steps of forming a gate oxide film and a gate electrode on a semiconductor substrate; implanting impurity ions of the same conductivity as the substrate in an oblique direction at a first tilt angle to the normal line of the substrate and with a first acceleration voltage and dose, while rotating the substrate about the normal line thereof; implanting impurities of the same conductivity as the substrate in the same manner except for using a tilt angle to the normal line which is greater and a dose which is smaller than that of the first tilt angle and dose; and forming source and drain regions by implanting impurity ions of the opposite conductivity to the substrate into the substrate, followed by performing a thermal treatment.

Abstract: A high saturation current, low leakage, Fermi threshold field effect transistor includes a predetermined minimum doping concentration of the source and drain facing the channel to maximize the saturation current of the transistor. Source and drain doping gradient regions between the source/drain and the channel, respectively, of thickness greater than 300.ANG. are also provided. The threshold voltage of the Fermi-FET may also be lowered from twice the Fermi potential of the substrate, while still maintaining zero static electric field in the channel perpendicular to the substrate, by increasing the doping concentration of the channel from that which produces a threshold voltage of twice the Fermi potential. By maintaining a predetermined channel depth, preferably about 600.ANG., the saturation current and threshold voltage may be independently varied by increasing the source/drain doping concentration facing the channel and by increasing the excess carrier concentration in the channel, respectively.

Abstract: An insulated gate semiconductor device (10) having a pseudo-stepped channel region (20B) between two P-N junctions (21B and 22B). The pseudo-stepped channel region (20B) is comprised of an enhancement mode portion (26B) and a depletion mode portion (28B), the enhancement mode portion (26B) being more heavily doped than the depletion mode portion (28B). One P-N junction (21B) is formed at an interface between a source region (18B) and the enhancement mode portion (26B). The enhancement mode portion (26B) has a substantially constant doping profile, thus slight variations in the placement of the source region (18B) within the enhancement region (26B) do not result in significant variations in the threshold voltage of the insulated gate semiconductor device (10). The insulated gate semiconductor device (10) is well suited for the design of low voltage circuits because of the small variations of the threshold voltage.

Abstract: A semiconductor device with a semiconductor body (1) includes a surface region (3) of a first conductivity type which adjoins a surface and in which a field effect transistor is provided which includes a channel region (7) with a gate electrode (8) above it, and a source region (4), a drain region (5) and a drain extension region (6). The drain extension region (6) serves to improve the drain breakdown voltage of the field effect transistor. In practice, a high breakdown voltage is accompanied by a comparatively high on-resistance of the transistor. According to the invention, the drain extension region (6) has a geometry different from that in known transistors, i.e.

Abstract: A flash electrically erasable programmable read only memory (EEPROM) device includes a two-dimensional array of single transistor non-volatile memory cells having the mid channel injection mechanism. The single transistor non-volatile memory cell includes a select gate, a control gate, and a floating gate which are disposed above a channel between a source and a drain. The control gate is located above the floating gate. In order to program the memory cell, the carrier injection into the floating gate is accomplished by the deflection of accelerated carriers from the middle region of the channel. Carriers are accelerated through the carrier acceleration passage by the horizontal component of the stray electric field, and deflected by the vertical component of the electric field. The erasure of memory cell is accomplished by the tunneling of carriers from the floating gate to the drain.

Abstract: A field effect transistor includes a gate electrode disposed on a first conductivity type semiconductor substrate via an insulating film, a second conductivity type region having a first dopant impurity concentration region in the substrate at the drain side of the gate electrode contacting the insulating film, a second conductivity type region in the substrate having a higher dopant impurity concentration than the first dopant impurity concentration at the source side of the gate electrode contacting the insulating film, and a first conductivity type region in the substrate having a higher dopant impurity concentration than the substrate and surrounding the source region in the substrate. The ON-resistance of the transistor is reduced. The first conductivity type region improves the drain-source breakdown voltage, suppresses variations in the threshold voltage, and reduces the gate-source and gate-drain capacitances.

Abstract: A MOSFET device for ULSI circuits includes a semiconductor body having first and second spaced doped regions of a first conductivity type which function as source and drain regions, a third doped region between the first and second regions of a second conductivity type, and a first intrinsic region between the third doped region and the drain region, a channel of said MOSFET device including the third doped region and said first intrinsic region. Preferably the device further includes a second intrinsic region between the third doped region and the source region, the channel region of the MOSFET device including the third doped region, the first intrinsic region, and the second intrinsic region. The device further includes an insulating layer over the channel region and a gate electrode formed on the insulating layer over the channel region. A source electrode contact, the first doped region, and a drain electrode contact the second doped region. Several processes are described for fabricating the device.

Abstract: A semiconductor device which comprises a semiconductor substrate having thereon a channel region, said channel region comprising (A) a channel, and (B) a metallic layer or a compound layer of a metal with a constituent material of the semiconductor substrate, provided that at least a part of said metallic layer or said compound layer is included in said channel. The semiconductor device has stable characteristics with high operation speed, and yet, is capable of being fabricated by a simple process.

Abstract: A FET which can be formed on a silicon substrate and which can operate in the enhancement mode. The n+ source and drain are centrally located within n-wells which extend under the gate area, and are separated by a distance. By appropriately choosing the distance between n-wells, different threshold voltages can be obtained for several transistors on the same chip.

Abstract: An MOS transistor wherein the channel between the source and drain is formed with two regions having different dopant concentrations. The region adjacent the source has a normal concentration, while that adjacent the drain has a reduced dopant concentration. This reduces the degrading effects of hot carrier injection, thereby extending the life of the transistor.

Abstract: A semiconductor device with a non-uniformly and lightly doped channel comprises a gate electrode formed on a silicon substrate of first conductivity through the intermediary of a gate oxide dielectric film, and an extension of each side walls of the gate electrode composed of a thin polysilicon layer which is substantially thinner than the gate electrode, the silicon substrate having a channel region in which its central part is doped with ions of first conductivity at a concentration higher than in the silicon substrate and its part below the thin polysilicon layer is doped with ions of first conductivity at a concentration higher than in the central part, and having at an outer region of the channel region a source-drain region doped with ions of second conductivity.

Abstract: An NMOS transistor has a source and a drain composed of n+ type of semiconductor material. A substrate region composed of a p type of semiconductor material is disposed between the source and the drain. A gate region is disposed above the substrate region and between the source region and the drain region. A first implant region is disposed adjacent to the source region and the gate region. The first implant region is composed of p type of semiconductor material with a first doping concentration. A second implant region is disposed between the first implant region and the substrate. The second implant region is composed of p type of semiconductor material with a second doping concentration. The channel doping profile first and second implant regions is tailored to obtain the optimum internal electric field to maximize device transconductance, while simultaneously controlling the device threshold voltage and punch through characteristics.

Abstract: A semiconductor integrated circuit apparatus has a basic cell region formed by arranging a plurality of basic cells each including a MOS transistor in longitudinal and transversal directions. The MOS transistor has source-drain section diffusive regions formed on a semiconductor substrate, and a gate electrode formed on a channel region between these source-drain section diffusive regions through a gate insulating film. One portion or all of the channel region of at least one MOS transistor within the basic cell region has an impurity concentration different from that in the channel region of another MOS transistor of the same conductivity type within the same basic cell. For example, a threshold voltage in the channel region of a MOS transistor is increased until about 6 volts by implanting ions into the channel region. No MOS transistor is operated at a power voltage such as 5 volts and separates MOS transistors on both sides thereof from each other.

Abstract: A semiconductor memory device having a non-volatile memory transistor and a selection transistor formed near the non-volatile memory transistor. The channel region surface of the memory transistor is formed to have the same conductivity type with a lower density than the channel region surface of the selection transistor or opposite conductivity type so that the characteristic of the memory transistor shifts to the negative side resulting in a sufficient read margin for an erased cell even at a control voltage of 0.

Abstract: An electrically programmable and electrically erasable memory cell (EEPROM) formed in a silicon body is described. The cell includes a silicon body or substrate with shallow trench isolation regions disposed therein. First and second spaced-apart source and drain regions of a first conductivity type are provided with a channel region in between. A first gate member, a floating gate, which is completely surrounded by insulation extends from at least the edge of the source region, over the channel region to at least the edge of the drain region. A second gate member, a control gate, includes a portion which extends over the floating gate. The control gate extends from at least the edge of the source region, over the channel region to at least the edge of the drain region. The channel region beneath the floating gate has both a highly doped portion and a lightly doped portion.