Abstract: A plasma processing method performs a plasma processing on a substrate mounted on a mounting table installed in an airtight processing chamber, the mounting table having a smaller size than the substrate. The substrate having a surface, on which a resist mark is formed, is mounted on the mounting table and then electrostatically adsorbed on the mounting table by applying a voltage to an electrostatic chuck. The surface of the substrate is etched by using a plasma of an etching gas while the substrate is cooled through a heat transfer between the substrate and the mounting table via a thermally conductive gas supplied between a top surface of the mounting table and a bottom surface of the substrate. The supply of the thermally conductive gas is stopped, and the resist mask on the substrate is ashed by using a plasma of an ashing gas containing O2.

Abstract: The present invention leverages an etch-back process to provide an electrode cap for a polymer memory element. This allows the polymer memory element to be formed within a via embedded in layers formed on a substrate. By utilizing the etch-back process, the present invention provides tiny electrical contacts necessary for the proper functioning of polymer memory devices that utilize the vias. In one instance of the present invention, one or more via openings are formed in a dielectric layer to expose an underlying layer. A polymer layer is then formed within the via on the underlying layer with a top electrode material layer deposited over the polymer layer, filling the remaining portion of the via. Excess portions of the top electrode material are then removed by an etching process to form an electrode cap that provides an electrical contact point for the polymer memory element.

Abstract: In a plasma processing system, including a plasma processing chamber, a method of optimizing the etch resistance of a substrate material is described. The method includes flowing pre-coat gas mixture into the plasma processing chamber, wherein the pre-coat gas mixture has an affinity for a etchant gas flow mixture; striking a first plasma from the pre-coat gas mixture; and introducing a substrate comprising the substrate material. The method also includes flowing the etchant gas mixture into the plasma processing chamber; striking a second plasma from the etchant gas mixture; and etching the substrate with the second plasma. Wherein the first plasma creates a pre-coat residual on a set of exposed surfaces in the plasma processing chamber, and the etch resistance of the substrate material is maintained.

Abstract: A semiconductor manufacturing process wherein a low-k dielectric layer is plasma etched with selectivity to an overlying mask layer. The etchant gas can be oxygen-free and include a fluorocarbon reactant, a nitrogen reactant and an optional carrier gas, the fluorocarbon reactant and nitrogen reactant being supplied to a chamber of a plasma etch reactor at flow rates such that the fluorocarbon reactant flow rate is less than the nitrogen reactant flow rate. The etch rate of the low-k dielectric layer can be at least 5 times higher than that of a silicon dioxide, silicon nitride, silicon oxynitride or silicon carbide mask layer. The process is useful for etching 0.25 micron and smaller contact or via openings in forming structures such as damascene structures.

Abstract: A method for forming a step channel of a semiconductor device is disclosed. The method for forming a step channel of a semiconductor device comprises forming a hard mask layer pattern defining a step channel region on a semiconductor substrate, forming a spacer on a sidewall of the hard mask layer pattern, and simultaneously etching the spacer and a predetermined thickness of the semiconductor substrate using the hard mask layer pattern and the spacer as an etching mask.

Abstract: A method for etching features in a silicon oxide based dielectric layer over a substrate, comprising performing an etch cycle. A lag etch partially etching features in the silicon oxide based dielectric layer is performed, comprising providing a lag etchant gas, forming a plasma from the lag etchant gas, and etching the etch layer with the lag etchant gas, so that smaller features are etched slower than wider features. A reverse lag etch further etching the features in the silicon oxide based dielectric layer is performed comprising providing a reverse lag etchant gas, which is different from the lag etchant gas and is more polymerizing than the lag etchant gas, forming a plasma from the reverse lag etchant gas, and etching the silicon oxide based dielectric layer with the plasma formed from the reverse lag etchant gas, so that smaller features are etched faster than wider features.

Abstract: A method of performing a double-sided process is provided. First, a wafer having a structural pattern disposed on the front surface is provided. Following that, a plurality of front scribe lines are defined on the structural pattern, and a filling layer is filled into the front scribe lines. Subsequently, the structural pattern is bonded to a carrier wafer with a bonding layer, and a plurality of back scribe lines are defined on the back surface of the wafer. Finally, the filling layer filled in the front scribe lines is removed.

Abstract: Gas switching is used during an etch process to modulate the characteristics of the etch. The etch process comprises a sequence of at least three steps, wherein the sequence is repeated at least once. For example, the first step may result in a high etch rate of oxide (108) while the second step is a polymer coating steps and the third step results in a low etch rate of oxide and high etch rate of another material (114) and/or sputtering.

Abstract: A method for forming a pattern is provided that includes: providing a cliché having a plurality of convex patterns; applying an adhesive force reinforcing agent onto each surface of the convex patterns; forming an etching object layer on a substrate and then applying ink onto an upper portion of the etching object layer; attaching the cliché and the substrate to each other such that the convex patterns onto which the adhesive force reinforcing agent is applied can come in contact with the ink applied onto the etching object layer; and forming ink patterns which selectively remain on the etching object layer by separating the substrate and the cliché from each other.

Abstract: Methods of etching a dielectric layer and a cap layer over a conductor to expose the conductor are disclosed. In one embodiment, the methods include the use of a silicon dioxide (SiO2) etching chemistry including octafluorocyclobutane (C4F8) and a titanium nitride (TiN) etching chemistry including tetrafluoro methane (CF4). The methods prevent etch rate degradation and exhibit reduced electro-static discharge (ESD) defects.

Abstract: A plasma etching method includes the step of performing a plasma etching on a silicon-containing dielectric layer formed on a substrate to be processed by using a plasma, while using an organic layer as a mask. In addition, the plasma is generated from a processing gas at least including a first fluorocarbon gas which is an unsaturated gas; a second fluorocarbon gas which is an aliphatic saturated gas expressed by CmF2m+2 (m=5, 6); and an oxygen gas. Further, a computer-readable storage medium for storing therein a computer executable control program is provided where the control program, when executed, controls a plasma etching apparatus to perform the above plasma etching method.

Abstract: The present invention includes a process for selectively etching a low-k dielectric material formed on a substrate using a plasma of a gas mixture in a plasma etch chamber. The gas mixture comprises a fluorine-rich fluorocarbon or hydrofluorocarbon gas, a nitrogen-containing gas, and one or more additive gases, such as a hydrogen-rich hydrofluorocarbon gas, an inert gas and/or a carbon-oxygen gas. The process provides a low-k dielectric to a photoresist mask etching selectivity ratio greater than about 5:1, a low-k dielectric to a barrier/liner layer etching selectivity ratio greater about 10:1, and a low-k dielectric etch rate higher than about 4000 ?/min.

Abstract: Methods are disclosed for forming dual stressed layers in such a way that both undercutting and an undesirable residual spacer of the first-deposited stressed layer are prevented. In one embodiment, a method includes forming a first stressed silicon nitride layer over the NFET and the PFET, forming a sacrificial layer over the first stressed silicon nitride layer such that the sacrificial layer is thinner over substantially vertical surfaces than over substantially horizontal surfaces, forming a mask over a first one of the NFET and the PFET, removing the first stressed silicon nitride layer over a second one of the NFET and the PFET, and forming a second stressed silicon nitride layer over the second one of the NFET and the PFET. The sacrificial layer prevents undercutting and forming of an undesirable residual spacer during removal of the first-deposited stressed layer.

Abstract: A method for forming a silicon oxynitride layer, suitable to be used in the production of semiconductor devices, e.g. poly-silicon thin film transistors, is provided. A plasma surface treatment is performed over a substrate after a silicon nitride/silicon oxide layer has been formed on the substrate by a glow discharge system to transform the silicon nitride/silicon oxide layer into a silicon oxynitride layer. The semiconductor device may be completely manufactured in simplex equipment. Therefore, the production time and production cost are favorably reduced.

Abstract: A mask material layer 102 of a desired pattern is formed on a silicon oxide film 101. The exposed parts of the silicon oxide film 101 is etched in accordance with the pattern of the mask material layer 102 by plasma etching by using a mixed gas fed at a rate such that the ratio (C5F8+O2/Ar) of the total flow rate of C5F8+O2 to the flow rate of Ar is 0.02 (2%) or less. Thus, a generally vertical right-angled portion is formed in the silicon oxide film 101. Therefore, no microtrenches are formed, and etching into a desired pattern is precisely effected.

Abstract: A method for etching a polysilicon gate structure in a plasma etch chamber is provided. The method initiates with defining a pattern protecting a polysilicon film to be etched. Then, a plasma is generated. Next, substantially all of the polysilicon film that is unprotected is etched. Then, a silicon containing gas is introduced and a remainder of the polysilicon film is etched while introducing a silicon containing gas. An etch chamber configured to introduce a silicon containing gas during an etch process is also provided.

Abstract: A method including introducing a dielectric layer over a substrate between an interconnection line and the substrate, the dielectric layer comprising a plurality of alternating material layers; and patterning an interconnection to the substrate. An apparatus comprising a substrate comprising a plurality of devices formed thereon; and an interlayer dielectric layer comprising a base layer and a cap layer, the cap layer comprising a plurality of alternating material layers overlying the substrate.

Abstract: Semiconductor devices having a contact window and fabrication methods thereof are provided. A lower dielectric layer, conductive patterns and an upper dielectric layer are formed sequentially on a semiconductor substrate. The lower dielectric layer has a higher isotropic etch rate than that of the upper dielectric layer. The upper dielectric layer and the lower dielectric layer are patterned by anisotropic etching to form a trench without exposing the semiconductor substrate. The resultant structure is subject to isotropic etching to expose the substrate and to form a contact window having a wider width in a lower region than in an upper region without damaging the semiconductor substrate.

Abstract: According to a method for producing a solid body (1) including a microstructure (2), the surface of a substrate (3) is provided with a masking layer (6) that is impermeable to a substance to be applied. The substance is then incorporated into the substrate regions not covered by the masking layer (6). A heat treatment is used to diffuse the substance into a substrate region covered by the masking layer (6) such that a concentration gradient of the substance is created in the substrate region covered by the masking layer (6), proceeding from the edge of the masking layer (6) inward with increasing distance from the edge. The masking layer (6) is then removed to expose the substrate region under this layer, and a near-surface layer of the substrate (3) in the exposed substrate region is converted by a chemical conversion reaction into a coating (9) which has a layer thickness profile corresponding to the concentration gradient of the substance contained in this near-surface layer.

Abstract: A patterned mask can be formed as follows. A first patterned photoresist is formed over a masking layer and utilized during a first etch into the masking layer. The first etch extends to a depth in the masking layer that is less than entirely through the masking layer. A second patterned photoresist is subsequently formed over the masking layer and utilized during a second etch into the masking layer. The combined first and second etches form openings extending entirely through the masking layer and thus form the masking layer into the patterned mask. The patterned mask can be utilized to form a pattern in a substrate underlying the mask. The pattern formed in the substrate can correspond to an array of capacitor container openings. Capacitor structure can be formed within the openings. The capacitor structures can be incorporated within a DRAM array.

Abstract: A semiconductor device includes a semiconductor device comprising a semiconductor substrate, source/drain regions formed in the semiconductor substrate, a gate insulation film formed on the semiconductor substrate, a gate electrode formed on the gate insulation film between the source/drain regions, and a gate sidewall spacer formed on side surfaces of the gate electrode, wherein the gate sidewall spacer is composed of silicon oxide containing 0.1–30 atomic % of chlorine.

Abstract: A method of fabricating an integrated circuit, having copper metallization formed by a dual damascene process, is disclosed. A layered insulator structure is formed over a first conductor (22), within which a second conductor (40) is formed to contact the first conductor. The layered insulator structure includes a via etch stop layer (24), an interlevel dielectric layer (26), a trench etch stop layer (28), an intermetal dielectric layer (30), and a hardmask layer (32). The interlevel dielectric layer (26) and the intermetal dielectric layer (30) are preferably of the same material. A via is partially etched through the intermetal dielectric layer (30), and through an optional trench etch stop layer (28). A trench location is then defined by photoresist (38), and this trench location is transferred to the hardmask layer (32).

Abstract: A system and method is disclosed for providing a dry-wet-dry etch procedure to create a sidewall profile of a via in a semiconductor device. A first vertical anisotropic dry etch process is applied to etch through a first portion of a dielectric layer. An isotropic wet etch process is then applied to etch a sloping surface in the sidewalls of the via cavity. A second vertical anisotropic dry etch process is then applied to extend the sloping sidewalls of the via cavity down to a substrate of the semiconductor device. The smooth sloping surfaces of the sidewalls are formed without a prior art concave surface of the type that interferes with a via fill process.

Abstract: The present invention provides a method for preventing the defect the in shape of via holes cased when an alumina mask is used for the dry etching of an interlayer insulator composed of an SiOC film in the dual damascene process in which via holes are formed prior to forming wiring trenches. That is, after forming an alumina mask on an interlayer insulator composed of a low-k SiOC film via a cap insulator, the cap insulator and the interlayer insulator are dry-etched with using a photoresist film as a mask to form via holes. Next, after removing the photoresist film, the inside of the via holes are cleaned by using dilute hydrofluoric acid solution to remove alumina residue. Thereafter, the cap insulator and the interlayer insulator are dry-etched with using the alumina mask as a mask to form wiring trenches.

Abstract: The present invention provides method and apparatus for surface treatment which, when employed in process steps of manufacturing semiconductor devices, can result in the final products having enhanced reliability. According to the surface processing method, an object to be processed W is introduced in a processing vessel 10, which is then supplied with ClF3 gas serving as cleaning gas from a supply unit 26. The ClF3 gas is bound to the surface of the object to be processed W, and although the supply of the gas to the processing vessel is interrupted, the ClF3 gas bound to the surface of the object to be processed W serves to clean the surface of the object to be processed. Next, reducing gas is introduced into the processing vessel W to remove chlorine from the object to be processed W, the chlorine being derived from the ClF3 gas. After that, the introduction of the reducing gas is interrupted, and the cleaned object to be processed W is exported from the processing vessel 10.

Abstract: According to one embodiment, a method (100) may include forming a first insulating layer over a semiconductor substrate (step 102), forming a hard mask layer (step 104), and forming a photoresist etch mask having a thickness of less than about 4,000 angstroms (step 106). Such a reduced thickness may conventionally lead to uncontrolled etching and/or may require multiple steps to ensure feature formation. A method (100) may further include etching an opening through at least one half the thickness of the hard mask layer to form a hard mask (step 108) and etching through a first insulating layer without first removing a photoresist layer (step 110). Such etching can essentially consume a photoresist layer, however controllability can be maintained as etching may continue with a hard mask in place.

Abstract: Method and apparatus for etching a metal layer disposed on a substrate, such as a photolithographic reticle, are provided. In one aspect, a method is provided for processing a photolithographic reticle including positioning the reticle in a first orientation on a reticle support in a processing chamber, wherein the reticle comprises a metal photomask layer formed on an optically transparent substrate, and a patterned resist material deposited on the metal photomask layer, etching the metal photomask layer in the first orientation, positioning the reticle in at least a second orientation, and etching the metal photomask layer in the at least second orientation.

Abstract: A method for etching silicon nitride selective to silicon dioxide and silicon (polycrystalline silicon or monocrystalline silicon) comprises the use of oxygen along with an additional etchant of either CHF3 or CH2F2. Flow rates, power, and pressure settings are specified.

Abstract: A process for controlling the plasma etch of a silicon dioxide layer at a high etch rate and high selectivity with respect to silicon nitride, particularly in a multilayer structure, by (1) maintaining various portions of the etch chamber at elevated temperatures, and/ox (2) using an etch chemistry having a fluorohydrocarbon gas containing at least as many hydrogen atoms as fluorine atoms, preferably CH2F2 or CH3F.

Abstract: Methods of etching a dielectric layer and a cap layer over a conductor level to open a via to the conductor. The methods include the provision of tetrafluoro methane (CF4) in a photoresist strip. In addition, the methods may provide an increased amount of tetrafluoro methane (CF4) in a dielectric layer etch, and trifluoro methane (CHF3) in a cap layer etch. The invention provides higher yield, more predictable etch rates, faster processing, and removes the need for an ash step.

Abstract: This invention relates to a method for self-aligned fabricating an isolation structure of a trench capacitor. The method takes two steps to etch the substrate for forming the shallow trench of the isolation structure, wherein the conductive layer and the collar oxide layer of the trench capacitor remain intact during the etching processes.

Abstract: A method of removing an oxide layer from an article. The article may be located in a reaction chamber into which an interhalogen compound reactive with the oxide layer is introduced. A temperature of the reaction chamber may be modified so as to remove the oxide layer. The interhalogen compound may form volatile by-product gases upon reaction with the oxide layer. Unreacted interhalogen compound and volatile by-product gases may then be removed from the reaction chamber.

Abstract: A method and system for forming a low defect oxide in a plasma processing chamber. By pulsing at least one of an RF power source and a processing gas, the growth of the oxide can be regulated. During periods in which the processing gas is not injected, an inert gas is injected to keep a substantially constant flow rate.

Abstract: A method and apparatus that produces highly ordered, nanosized particle arrays on various substrates. These regular arrays may be used as masks to deposit and grow other nanoscale materials.

Abstract: A semiconductor device manufacturing method is provided where a device structure is formed on top of a wafer that comprises a backside semiconductor substrate, a buried insulator layer and a top semiconductor layer. Then, an etch stop layer is formed upon the wafer that carries the device structure, and a window is formed in the etch stop layer. Further, a dielectric layer is formed upon the etch stop layer that has the window. Then, a first contact hole through the dielectric layer and the window down to the backside semiconductor substrate is simultaneously etched with at least one second contact hole through the dielectric layer down to the device structure. The wafer may be a silicon-on-insulator (SOI) wafer, and the etch stop layer and the dielectric layer may be formed by depositing silicon oxynitride and tetraethyl orthosilicate (TEOS), respectively. The device structure may be a CMOS transistor structure.

Abstract: A method for etching a silicon on insulator (SOI) substrate includes opening a hardmask layer formed on an SOI layer, and etching through the SOI layer, a buried insulator layer underneath the SOI layer, and a bulk silicon layer beneath the buried insulator layer using a single etch step.

Abstract: A low k dielectric layer is formed on a surface of a substrate of a semiconductor wafer. Then, a surface treatment is performed to the low k dielectric layer to form a passivation layer on a surface of the low k dielectric layer. A patterned photoresist layer is formed over the surface of the semiconductor wafer. The patterned photoresist layer is then used as a hard mask to perform an etching process on the low k dielectric layer. Finally, a stripping process is performed to remove the patterned photoresist layer. The passivation layer is used to prevent deterioration of the dielectric characteristic of the low k dielectric layer during the stripping process.

Abstract: A process and intermediate DRAM structure formed by providing a substrate having an array of trenches containing trench capacitors underlying vertical transistors in an array area separated by isolation trenches residing in both array and support areas. A top oxide nitride (TON) liner is deposited over array and support areas so as to directly contact the fill in the isolation trenches. An array top oxide (ATO) is then deposited directly over the TON liner such that during subsequent processing, the TON protects the isolation trench oxide from any divot opening etches while maintaining the isolation trench oxide height fixed during the ATO process. In further processing the intermediate structure, ATO and TON are removed from the support area only, leaving remaining portions of both ATO and TON only in the array area, such that the TON liner separates the ATO from the isolation trench fill.

Abstract: A chromeless phase lithography mask (30) that does not require photoresist to manufacture has a quartz substrate (32) is etched by using a plasma (38) containing one of a nitrogen augmented hydro-fluorocarbon oxygen mixture and a nitrogen augmented fluorocarbon oxygen mixture. Various hydro-fluorocarbons or fluorocarbons may be used. The nitrogen addition results in etched openings in the quartz substrate that have substantially vertical sidewalls in a uniform manner across the substrate. Surface roughness is minimized and edges of the openings are well-defined with minimal rounding. The etch rate is rendered controllable by reducing bias power without degrading a desired vertical sidewall profile.

Abstract: Three fundamental and three derived aspects of the present invention are disclosed. The three fundamental aspects each disclose a process sequence that may be integrated in a full process. The first aspect, designated as “latent masking”, defines a mask in a persistent material like silicon oxide that is held abeyant after definition while intervening processing operations are performed. The latent oxide pattern is then used to mask an etch. The second aspect, designated as “simultaneous multi-level etching (SMILE)”, provides a process sequence wherein a first pattern may be given an advanced start relative to a second pattern in etching into an underlying material, such that the first pattern may be etched deeper, shallower, or to the same depth as the second pattern. The third aspect, designated as “delayed LOCOS”, provides a means of defining a contact hole pattern at one stage of a process, then using the defined pattern at a later stage to open the contact holes.

Abstract: A method for removing silicon dioxide residuals is disclosed. The method includes reacting a portion of a silicon dioxide layer (i.e., oxide) to form a reaction product layer, removing the reaction product layer and annealing in an environment to remove oxide residuals. The method finds application in a variety of semiconductor fabrication processes including, for example, fabrication of a vertical HBT or silicon-to-silicon interface without an oxide interface.

Abstract: Methods for protecting the sidewall of a metal interconnect component using Physical Vapor Deposition (PVD) processes and using a single barrier metal material. After forming the metal interconnect component, a single barrier metal is deposited on its sidewall using PVD. A subsequent anisotropic etching of the barrier metal removes the barrier metal from the horizontal surface except for some that still remains on the top surface of the metal interconnect layer. A dielectric layer is then formed over the metal interconnect component and the barrier metal. The unlanded via is etched through the dielectric layer to the metal interconnect component, and then filled with a second metal to thereby allow the metal interconnect component to electrically connect with one or more upper metal layers.

Abstract: A method of reducing trench aspect ratio. A trench is formed in a substrate. A conformal Si-rich oxide layer is formed on the surface of the trench by HDPCVD. A conformal first oxide layer is formed on the Si-rich oxide layer by HDPCVD. A conformal second oxide layer is formed on the first oxide layer by LPCVD. Part of the Si-rich oxide layer, the second oxide layer and the first oxide layer are removed by anisotropic etching to form an oxide spacer composed of a remaining Si-rich oxide layer, a remaining second oxide layer and a remaining first oxide layer. The remaining second oxide layer, part of the remaining first oxide layer and part of the Si-rich oxide layer are removed by BOE. Thus, parts of the remaining first and Si-rich oxide layers are formed on the lower surface of the trench, thereby reducing the trench aspect ratio.

Abstract: The invention encompasses methods of forming silicide interconnects over silicon comprising substrates. In one implementation, a first layer comprising a metal and a non-metal impurity is formed over a region of a silicon comprising substrate where a silicide interconnection is desired. An elemental metal comprising second layer is formed over the first layer. The substrate is annealed to cause a reaction between at least the elemental metal of the second layer and silicon of the substrate region to form a silicide of the elemental metal of the second layer. In another considered aspect, a method of forming a silicide interconnect over a silicon comprising substrate includes providing a buffering layer to silicon diffusion between a refractory metal comprising layer and a silicon containing region of a substrate.

Abstract: Methods of manufacturing semiconductor devices are disclosed. In a disclosed example, a multi-layered insulating structure is deposited on a semiconductor substrate, an opening is formed in the multi-layered insulating structure above the semiconductor substrate, and a trench is formed in the semiconductor substrate under the opening. Then, a groove is formed on an edge position of an intermediate layer of the multi-layered insulating structure by wet-etching the intermediate layer of the multi-layered insulating layer transversely using a pull back process. Then, a liner oxide layer is deposited on the groove and the trench. An oxide layer then fills the trench and the groove without generating voids or divots in the oxide layer of the trench.

Abstract: A method of rapid etching of an insulating film including an organic-based dielectric film without forming a damage layer or causing decline of the throughput, including the steps of forming an insulating film including an organic-based dielectric film such as a stacked film comprised of a polyarylether film or other organic-based dielectric film and a silicon oxide-based dielectric film or other insulating film, forming a mask layer by patterning above the insulating film, and when etching the organic-based dielectric film portion, using ions or radicals containing NH group generated by gaseous discharge in a mixed gas of hydrogen gas and nitrogen gas or a mixed gas of ammonia gas for etching using the mask layer as an etching mask, to etch the insulating layer and form openings etc. while generating reaction products containing CN group.

Abstract: A method for forming a photoresist pattern with minimally reduced transformations through the use of ArF photolithography, including the steps of: forming an organic anti-reflective coating layer on a an etch-target layer already formed on a substrate; coating a photoresist for ArF on the organic anti-reflective coating layer; exposing the photoresist with ArF laser; forming a first photoresist pattern by developing the photoresist, wherein portions of the organic anti-reflective coating layer are revealed; etching the organic anti-reflective coating layer with the first photoresist pattern as an etch mask and forming a second photoresist pattern by attaching polymer to the first photoresist pattern, wherein the polymer is generated during etching the organic anti-reflection coating layer with an etchant including O2 plasma; and etching the etch-target layer by using the second photoresist pattern as an etch mask.

Abstract: A semiconductor film serving as an active region of a thin film transistor and an upper oxide film protecting the semiconductor film are dry etched to form the active region. In this case, a fluorine-based gas is used as the etching gas, and the etching gas is switched from the fluorine-based gas to a chlorine-based gas at a point of time when a lower oxide film as an underlying film of the semiconductor film is exposed. As the fluorine-based gas, a mixed gas of CF4 and O2 is used, and suitably, a gas ratio of CF4 and O2 in the mixture gas is set at 1:1, and the dry etching is performed therefor. By this etching, a side face of a two-layer structure of the semiconductor film and upper oxide film is optimally tapered, and a crack or a disconnection is prevented from being occurring in a film crossing over the two-layer structure.

Abstract: The present invention provides an auxiliary semiconductor device fabrication method that forms wiring 113 by using the wiring groove 108 that is formed in the sacrificial oxide film 104. An interlayer insulating film is formed by removing, by means of etching, the sacrificial oxide film that is used as a mold for the wiring layer formation and then allowing the porous Low-k film to fill the region from which the sacrificial oxide film has been removed.

Abstract: A trench transistor with lower leakage current and higher gate rupture voltage. The gate oxide layer of a trench transistor is grown at a temperature above about 1100° C. to reduce thinning of the oxide layer at the corners of the trench. In a further embodiment, a conformal layer of silicon nitride is deposited over the high-temperature oxide layer, and a second oxide layer is formed between the silicon nitride layer and the gate polysilicon. The first gate oxide layer, silicon nitride layer, and second oxide layer form a composite gate dielectric structure that substantially reduces leakage current in trench field effect transistors.