Abstract: The present invention relates to semiconductor devices, and more particularly to a structure and method for forming memory cells in a semiconductor device using a patterning layer and etch sequence. The method includes forming trenches in a layered semiconductor structure, each trench having an inner sidewall adjacent a section of the layered semiconductor structure between the trenches and an outer sidewall opposite the inner sidewall. The trenches are filled with polysilicon and the patterning layer is formed over the layered semiconductor structure. An opening is then patterned through the patterning layer, the opening exposing the section of the layered semiconductor structure between the trenches and only a vertical portion of the polysilicon along the inner sidewall of each trench. The layered semiconductor structure is then etched. The patterning layer prevents a second vertical portion of the polysilicon along the outer sidewall of each trench from being removed.

Abstract: Semiconductor devices with an improved overlay margin and methods of manufacturing the same are provided. In one aspect, a method includes forming a buried bit line in a substrate; forming an isolation layer in the substrate to define an active region, the isolation layer being parallel to the bit line without overlapping the bit line; and forming a gate line including a gate pattern and a conductive line by forming the gate pattern in the active region and forming a conductive line that extends at a right angle to the bit line across the active region and is electrically connected to the gate pattern disposed thereunder. The gate pattern and the conductive line can be integrally formed.

Abstract: A capacitor and method of manufacturing the same include an insulating interlayer, a lower electrode, a protection structure, a dielectric layer and an upper electrode. The insulating interlayer may include a conductive pattern formed on a substrate. The lower electrode may be electrically connected to the conductive pattern. The protection structure may be formed on an outer sidewall of the cylindrical lower electrode and on the insulating interlayer.

Abstract: In a trench MOSFET, the lower portion of the trench contains a buried source electrode, which is insulated from the epitaxial layer and semiconductor substrate but in electrical contact with the source region. When the MOSFET is in an “off” condition, the bias of the buried source electrode causes the “drift” region of the mesa to become depleted, enhancing the ability of the MOSFET to block current. The doping concentration of the drift region can therefore be increased, reducing the on-resistance of the MOSFET. The buried source electrode also reduces the gate-to-drain capacitance of the MOSFET, improving the ability of the MOSFET to operate at high frequencies. The substrate may advantageously include a plurality of annular trenches separated by annular mesas and a gate metal layer that extends outward from a central region in a plurality of gate metal legs separated by source metal regions.

Abstract: A semiconductor device includes an isolation layer disposed in a semiconductor device to define an active region. A gate trench is disposed across the active region and extends to the isolation layer. An insulated gate electrode fills a portion of the gate trench and covers at least one sidewall of the active region. A portion of the gate electrode, that covers at least one sidewall of the active region, extends under a portion of the gate electrode that crosses the active region. An insulating pattern is disposed on the gate electrode.

Abstract: A capacitor having a suitably large value for decoupling applications is formed in a trench defined by isolation structures such as recessed isolation or shallow trench isolation. The capacitor provides a contact area coextensive with an active area and can be reliably formed individually or in small numbers. Plate contacts are preferably made through implanted regions extending to or between dopant diffused regions forming a capacitor plate. The capacitor can be formed by a process subsequent to formation of isolation structures such that preferred soft mask processes can be used to form the isolation structures and process commonality and compatibility constraint are avoided while the capacitor forming processes can be performed in common with processing for other structures.

Abstract: A static random access memory (SRAM) cell structure at least comprising a substrate, a transistor, an upper electrode and a capacitor dielectric layer. A device isolation structure is set up in the substrate to define an active region. The active region has an opening. The transistor is set up over the active region of the substrate. The source region of the transistor is next to the opening. The upper electrode is set up over the opening such that the opening is completely filled. The capacitor dielectric layer is set up between the upper electrode and the substrate.

Abstract: A method for manufacturing a semiconductor device includes forming a device isolation film by a double Shallow Trench Isolation (STI) process, forming a first active region having a negative slope and a second active region having a positive slope. Additionally, the method includes applying a recess region and a bulb-type recess region to the above-extended active region so as to prevent generation of horns in the active regions. This structure results in improvement in effective channel length and area.

Abstract: An SOI layer has an initial trench extending therethrough, prior to deep trench etch. An oxidation step, such as thermal oxidation is performed to form a band of oxide on an inner periphery of the SOI layer to protect it during a subsequent RIE step for forming a deep trench. The initial trench may stop on BOX underlying the SOI. The band of oxide may also protect the SOI during buried plate implant or gas phase doping.

Abstract: A semiconductor device and related method of manufacture are disclosed. The device comprises; a trench having a corner portion formed in the semiconductor substrate, a first oxide film formed on an inner wall of the trench and having an upper end portion exposing the corner portion of the semiconductor substrate, a nitride liner formed on the first oxide film, a second oxide film formed in contact with the upper end of the first oxide film and on the exposed corner portion and an upper surface of the semiconductor substrate, a field insulating film formed on the nitride liner to substantially fill the trench, and a field protecting film formed in contact with the second oxide film and filling a trench edge recess formed between the field insulating film and the second oxide film.

Abstract: A method for forming a surface strap includes forming a deep trench capacitor having a conductive connection layer on its surface in the substrate and the conductive connection layer in contact with the conductive layer; forming a poly-Si layer covering the pad layer and the conductive connection layer; performing a selective ion implantation with an angle to make part of the poly-Si layer an undoped poly-Si layer; removing the undoped poly-Si layer to expose part of the conductive connection layer; etching the exposed conductive connection layer to form a recess; removing the poly-Si layer to make the exposed conductive connection layer a conductive connection strap; filling the recess with an insulation material to form a shallow trench isolation; exposing the conductive layer; and selectively removing the conductive layer to form a first conductive strap which forms the surface strap together with the conductive connection strap.

Abstract: A method of manufacturing a memory device. The memory device comprises a trench in a substrate, a capacitor at the low portion of the trench, a collar dielectric layer overlying the capacitor and covering a portion of the sidewall of the trench, and a conductive layer filling a portion of the trench over the capacitor. First, a first mask layer is formed on the conductive layer, wherein a bottom portion of the first mask layer is thicker than the side portion thereof in the trench. A second mask layer is formed on the first mask layer. Next, a portion of the second mask layer in the trench is ion implanted. The unimplanted portion of the second mask layer is removed.

Abstract: A method of making a semiconductor device is disclosed. A semiconductor body, an STI region, a gate and a silicided source/drain region are provided. The STI area is etched, and a liner is formed at the upper surface.

Abstract: A trench memory filled with a monolithic conducting material and methods for forming the same are disclosed. The trench memory includes a trench that has only a single, monolithic conducting material within the trench. The method includes forming a trench with a collar in the trench; forming a node dielectric on a sidewall of the trench; and filling the trench with a monolithic conducting material, such as polysilicon.

Abstract: A deep trench is formed in a semiconductor substrate. The deep trench may comprise a pair of parallel substantially vertical sidewalls having a constant separation distance. A set of outer substantially vertical sidewalls may have a closed shape in a horizontal cross-section. At least one dielectric layer is formed in the deep trench. The deep trench is filled with at least one conductive trench fill material to form a conductive deep trench fill region. A shallow trench isolation structure is formed directly on the deep trench to encapsulate the conductive deep trench fill region therebeneath. The stack of the deep trench and the shallow trench isolation structure form a deep trench inter-well isolation structure that provides electrical isolation of devices on one side of the stack from devices on the other side.

Abstract: It is disclosed a semiconductor device including a silicon substrate, provided with a plurality of cell active regions in a call region, an element isolation groove, formed in a portion, between any two of the plurality of cell active region, of the silicon substrate, a capacitor dielectric film, formed in the element isolation groove, a capacitor upper electrode, formed on the capacitor dielectric film, and configuring a capacitor together with the silicon substrate and the capacitor dielectric film. The semiconductor device is characterized in that a dummy active region is provided next to the cell region in the silicon substrate.

Abstract: A method creates semiconductor device in which a storage dielectric film and a storage electrode included in the capacitor is transferred from an inactive region of a semiconductor substrate to the active region thereof, i.e., into a device isolating trench such that the capacitor is prevented from unnecessarily occupying an active region of a semiconductor substrate while maintaining its proper function. In contrast to a conventional device where a capacitor is formed in the active region of the semiconductor substrate, to the capacitor is formed in the inactive region according to this process. Accordingly, the capacitor is able to maintain a trench structure without needing to perform a step of removal of a step height difference, and the active region is minimized in size. Therefore, without having a problem of a step height increase, a finished semiconductor device is able to accommodate modern demands for increased device interpretation.

Abstract: A dielectric interlayer, especially for a storage capacitor, is formed from a layer sequence subjected to a temperature process, wherein the layer sequence has at least a first metal oxide layer and a second metal oxide layer formed by completely oxidizing a metal nitride layer to higher valency.

Abstract: A trench capacitor with an isolation collar in a semiconductor substrate where the substrate adjacent to the isolation collar is free of dopants caused by auto-doping. The method of fabricating the trench capacitor includes the steps of forming a trench in the semiconductor substrate; depositing a dielectric layer on a sidewall of the trench; filling the trench with a first layer of undoped polysilicon; etching away the first layer of undoped polysilicon and the dielectric layer from an upper section of the trench whereby the semiconductor substrate is exposed at the sidewall in the upper section of the trench; forming an isolation collar layer on the sidewall in the upper section of the trench; and filling the trench with a second layer of doped polysilicon.

Abstract: Disclosed is a metal-insulator-metal (MIM) capacitor structure formed by a metal interconnection process of trench-exposed metal layers formed on stacked interlayer insulating layers. The MIM capacitor uses a conductive layer conformally formed on the metal interconnection and/or trench regions to enlarge constituent electrode surface areas.

Abstract: Embodiments relate to a method of manufacturing a semiconductor device.

Abstract: A fabrication process for a trench type power semiconductor device includes forming inside spacers over a semiconductor surface. Using the spacers as masks, trenches with gates are formed in the semiconductor body. After removing the spacers, source implants are formed in the semiconductor body along the trench edges and are then driven. Insulation caps are then formed over the trenches. Outside spacers are next formed along the sides of the caps. Using these spacers as masks, the semiconductor surface is etched and high conductivity contact regions formed. The outside spacers are then removed and source and drain contacts formed. Alternatively, the source implants are not driven. Rather, prior to outside spacer formation a second source implant is performed. The outside spacers are then formed, portions of the second source implant etched, any remaining source implant driven, and the contact regions formed. The gate electrodes are either recessed below or extend above the semiconductor surface.

Abstract: A method of fabricating a shallow trench isolation structure is provided. A substrate is provided with a pad layer, a mask layer and a shallow trench formed therein. A liner oxide layer is formed on the sidewall of the shallow trench and then a silicon nitride layer is formed conformably over the substrate. A developable material layer is formed to fill up the shallow trench. After the baking process, a part of the developable material layer is removed until the top surface of the developable material layer is lower than that of the substrate. The silicon nitride layer that is exposed by the developable material layer is removed and the remained developable material layer is removed. Following a thermal oxidation process, an insulating layer is formed over the substrate and fills up the shallow trench. After planarization and removing the mask layer, a shallow trench isolation structure is formed.

Abstract: Multiple trench depths within an integrated circuit device are formed by first forming trenches in a substrate to a first depth, but of varying widths. Formation of a dielectric layer can cause some of the trenches to fill or close off while leaving other, wider trenches open. Removal of a portion of the dielectric material can then be tailored to expose a bottom of the open trenches while leaving remaining trenches filled. Removal of exposed portions of the underlying substrate can then be used to selectively deepen the open trenches, which can subsequently be filled. Such methods can be used to form trenches of varying depths without the need for subsequent masking.

Abstract: On a substrate surface, which has been patterned in the form of a relief, of a substrate, typically of a semiconductor wafer, a deposition process is used to provide a covering layer on process surfaces which are vertical or inclined with respect to the substrate surface. The covering layer is patterned in a direction which is vertical with respect to the substrate surface by limiting a process quantity of at least one precursor material and/or by temporarily limiting the deposition process, and is formed as a functional layer or mask for subsequent process steps.

Abstract: A method of fabricating an a non-volatile memory includes forming trench isolation regions in an inactive region of a semiconductor substrate, adjacent trench isolation regions defining respective protrusions having rounded edges therebetween, wherein upper surfaces of the trench isolation regions are lower than an upper surface of the semiconductor substrate and wherein the protrusions define an active region, forming a tunnel insulating layer covering the protrusion of the semiconductor substrate, and forming, sequentially, a storage layer, a blocking insulating layer, and a gate layer covering the tunnel insulating layer.

Abstract: A process for producing a capacitor integrated into an electronic circuit comprises the formation of a trench in a substrate through a conductive portion similar to an MOS transistor gate. Alternating conductive, insulating and conductive layers are deposited inside the trench T in order to form a lower electrode, a dielectric and an upper electrode of the capacitor, respectively. The conductive portion is used to electrically connect the lower electrode to other electronic components of the circuit without an additional cost with respect to the connection of the circuit transistors.

Abstract: Fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected thereto on one side through a buried contact, in particular, for a semiconductor memory cell with a planar selection transistor in the substrate and connected through the buried contact, includes providing a trench using an opening in a hard mask, providing a capacitor dielectric in lower and central trench regions, the collar in central and upper trench regions, and a conductive filling at least as far as the insulation collar topside, completely filling the trench with a filling material, carrying out STI trench fabrication process, removing the filling material and sinking the filling to below the collar topside, forming an insulation region on one side above the collar; uncovering a connection region on a different side above the collar, and forming the buried contact by depositing and etching back a metallic filling.

Abstract: A well isolation trenches for a CMOS device and the method for forming the same. The CMOS device includes (a) a semiconductor substrate, (b) a P well and an N well in the semiconductor substrate, (c) a well isolation region sandwiched between and in direct physical contact with the P well and the N well. The P well comprises a first shallow trench isolation (STI) region, and the N well comprises a second STI region. A bottom surface of the well isolation region is at a lower level than bottom surfaces of the first and second STI regions. When going from top to bottom of the well isolation region, an area of a horizontal cross section of the well isolation region is an essentially continuous function.

Abstract: The invention includes semiconductor structures having buried silicide-containing bitlines. Vertical surround gate transistor structures can be formed over the bitlines. The surround gate transistor structures can be incorporated into memory devices, such as, for example, DRAM devices. The invention can be utilized for forming 4F2 DRAM devices.

Abstract: A process for fabricating a novel random access memory (RAM) capacitor in a shallow trench isolation (STI) The method utilizes a novel node photoresist mask for plasma etching recesses in the STI that prevents plasma-etch-induced defects in the substrate. This novel photoresist mask is used to etch bottle-shaped recesses in the STI under a first hard mask. After forming bottom electrodes in the recesses and forming an interelectrode dielectric layer, a conducting layer is deposited sufficiently thick to fill the recesses and to form a planar surface, and a second hard mask is deposited. The conducting layer is patterned to form the capacitor top electrodes. This reduced topography results in reduced leakage currents when the gate electrodes are formed over the capacitor top electrodes.

Abstract: The invention relates to a phase-change memory device. The device includes a lower electrode disposed in a recess of a first dielectric. The lower electrode comprises a first side and a second side. The first side communicates to a volume of phase-change memory material. The second side has a length that is less than the first side. Additionally, a second dielectric may overlie the lower electrode. The second dielectric has a shape that is substantially similar to the lower electrode. The present invention also relates to a method of making a phase-change memory device. The method includes providing a lower electrode material in a recess. The method also includes removing at least a portion of the second side.

Abstract: A memory cell includes a selection transistor and a trench capacitor. The trench capacitor is filled with a conductive trench filling on which an insulating covering layer is arranged. The insulating covering layer is laterally overgrown, proceeding from the substrate with a selectively grown epitaxial layer. The selection transistor is formed in the selectively grown epitaxial layer, comprises a source region connected to the trench capacitor and a drain region connected to a bit line. The junction depth of the source region is chosen so that the source region reaches as far as the insulating covering layer. Optionally, the thickness of the epitaxial layer can be reduced to a thickness by oxidation and a subsequent etching. Afterwards, a contact trench is etched through the source region down to the conductive trench filling, which trench is filled with a conductive contact and electrically connects the conductive trench filling to the source region.

Abstract: A structure and method are provided for forming a collar surrounding a portion of a trench in a semiconductor substrate, the collar having a lower edge self-aligned to a top edge of a buried plate disposed adjacent to a lower portion of the trench.

Abstract: According to some embodiments of the present invention, there are provided PRAMS having a phase-change layer pattern interposed between a molding layer and a forming layer pattern, and methods of forming the same that include a node conductive layer pattern, a molding layer, a forming layer pattern and a protecting layer. The molding layer, the forming layer pattern and the protecting layer are formed to cover the planarized interlayer insulating layer and the node conductive layer pattern. A lower electrode is interposed between the molding layer and the planarized interlayer insulating layer. A phase-change layer pattern is formed on the planarized interlayer insulating layer. A spacer pattern is disposed between the phase-change layer pattern and the molding layer.

Abstract: A buried strap contact between a trench capacitor of a memory cell and the subsequently formed selection transistor of the memory cell is fabricated such that the inner capacitor electrode layer is etched back in the trench of the trench capacitor and the uncovered insulator layer is then removed at the trench wall in order to define the region of the buried strap contact area. A liner layer is subsequently deposited in order to cover the inner capacitor electrode layer in the trench and the uncovered trench wall and thus to form a barrier layer. A spacer layer with the material of the inner electrode layer is then formed on the liner layer at the trench wall. Finally, the uncovered liner layer is removed above the inner electrode layer and the trench is filled with the material of the inner electrode layer in order to fabricate the buried strap contact.

Abstract: The surface area of the walls of a trench formed in a substrate is increased. A barrier layer is formed on the walls of the trench such that the barrier layer is thinner near the corners of the trench and is thicker between the corners of the trench. A dopant is introduced into the substrate through the barrier layer to form higher doped regions in the substrate near the corners of the trench and lesser doped regions between the corners of the trench. The barrier layer is removed, and the walls of the trench are etched in a manner that etches the lesser doped regions of the substrate at a higher rate than the higher doped regions of the substrate to widen and lengthen the trench and to form rounded corners at the intersections of the walls of the trench.

Abstract: A DRAM cell in a substrate has a deep trench (DT) extending from a surface of the substrate into the substrate, a word line (WL) formed on the surface of the substrate adjacent the deep trench, and oxide (TTO) disposed in a top portion of the trench and extending beyond the trench in the direction of the word line. In this manner, when silicided, there is oxide rather than silicon on the surface of the substrate in a gap between the word line (WL) and a passing word line (PWL) disposed above the deep trench.

Abstract: In a process for etching poly Si gate stacks with raised STI structure where the thickness of poly Si gates at the AA and STI are different, the improvement comprising: a) etching a gate silicide layer+a poly Si 2 layer; b) forming a continuous poly Si passivation layer on sidewalls of the silicide and poly Si 2 layers and at the interface of the poly Si 2 layer and a poly Si 1 layer and affecting thermal oxidation to form an underlying thin Si oxide gate layer; c) affecting a Si oxide breakthrough etch to clear the passivation layer at interface of the poly Si 2 and the poly Si 1 layers while leaving intact the passivation layer on the sidewalls of the silicide and the poly Si 2 layers; and d) etching the poly Si 1 layer with an oxide selective process to preserve the underlying thin gate oxide and thin passivation layer at the sidewall to obtain vertical profiles of poly Si gate stacks both at the AA and the STI oxide.

Abstract: A process is provided for forming a trench capacitor, such as used in a DRAM memory cell, in which the required number of polysilicon deposition steps and planarization steps are reduced. A first region of a first material is formed in the bottom portion of the trench, and a dielectric material for the collar structure is subsequently formed above this region on a portion of the trench sidewalls. A removable material, such as a resist or spin-on glass, is then provided in the trench, overlying the first material and in contact with the lower portion of the collar dielectric material. The upper portion of the collar structure is then removed, after which the removable material is removed to again expose the upper surface of the first region. A second region of a second material, overlying and in contact with the first region, is then formed; the second region has an upper surface below the surface of the substrate. The first and second materials are conducting materials, typically polysilicon.

Abstract: A method of fabricating a bottle trench and a bottle trench capacitor. The method including: providing a substrate; forming a trench in the substrate, the trench having sidewalls and a bottom, the trench having an upper region adjacent to a top surface of the substrate and a lower region adjacent to the bottom of the trench; forming an oxidized layer of the substrate in the bottom region of the trench; and removing the oxidized layer of the substrate from the bottom region of the trench, a cross-sectional area of the lower region of the trench greater than a cross-sectional area of the upper region of the trench.

Abstract: A method for fabricating a shallow trench isolation (STI) structure is described. A patterned mask layer is formed on a substrate. An ion implantation is performed to form a doped region in a predetermined depth in the substrate exposed by the mask layer. An etching process is conducted to etch the substrate down to the doped region to form a shallow trench. Thereafter, an isolating material is filled into the shallow trench to form an STI layer. The doped region is located directly under the STI layer, and no doped region is formed in the sidewall of the shallow trench.

Abstract: The present invention refers to a method of forming a silicon dioxide layer by thermally oxidizing at least one monocrystalline silicon surface region on a semiconductor substrate. The silicon surface region has a curved surface. The method can include providing a semiconductor substrate having at least one monocrystalline silicon surface region having a curved surface, roughening the surface of the at least one monocrystalline silicon surface region to produce a layer of porous silicon, and thermally oxidizing the at least one roughened monocrystalline silicon surface.

Abstract: Provided herein are vertical nanotube semiconductor devices and methods for making the same. An embodiment of the semiconductor devices comprises a vertical transistor/capacitor cell including a nanotube. The device includes a vertical transistor and a capacitor cell both using a single nanotube to form the individual devices.

Abstract: A method for forming a top oxide for a deep trench memory device comprising a poly stud above a polysilicon fill in a deep trench and an isolation region in a portion of the deep trench, comprises forming an etch support nitride liner by low-pressure chemical vapor deposition over the poly stud, and forming a support polysilicon over a portion of the isolation trench outside of an array. The method further comprises depositing a top oxide over the deep trench memory device, forming a planarization coating over the top oxide, and opening the nitride stud, wherein the top oxide remains over a portion of the isolation trench.

Abstract: This invention pertains to a method for making a trench capacitor of DRAM devices. A single-sided spacer is situated on the sidewall of a recess at the top of the trench capacitor prior to the third polysilicon deposition and recess etching process. The single-sided spacer is formed on the second polysilicon layer and collar oxide layer. Then, the third polysilicon deposition and recess etching process is carried out to form a third polysilicon layer on the second polysilicon layer. Dopants of the third polysilicon layer are blocked from diffusing to the substrate by the single-sided spacer.

Abstract: A method of manufacturing a lateral trench-type MOSFET exhibiting a high breakdown voltage and including an offset drain region around a trench. Specifically, impurity ions are irradiated obliquely to the side wall of a trench to implant the impurity ions only into to the portion of a semiconductor substrate along the side wall of trench, impurity ions are irradiated in parallel to the side wall of trench to implant the impurity ions only into to the portion of semiconductor substrate beneath the bottom wall of trench; the substrate is heated to drive the implanted impurity ions to form an offset drain region around trench and to thermally oxidize semiconductor substrate to fill the trench 2 with an oxide. Alternatively, the semiconductor substrate is oxidized to narrow trench with oxide films leaving a narrow trench and the narrow trench left is filled with an oxide.

Abstract: An electric field effect transistor of high breakdown voltage and a method of manufacturing the same are disclosed. A recessed portion is formed at the channel region and is filled by a protective oxide layer. Lightly doped source/drain regions are formed under the protective oxide layer. The protective oxide layer protects the lightly doped source/drain regions. Accordingly, the protective oxide layer prevents the electric field from being concentrated to a bottom corner portion of the gate structure. In addition, the effective channel length is elongated since an electric power source is connected to heavily doped source/drain regions from an outside source of the transistor, instead of being connected to lightly doped source/drain regions.

Abstract: At least not less than one capacitor formation trench providing an uneven surface is formed on the surface of a capacitor formation region. Thus, the surface area of a capacitor is increased, which enables improvement of the capacitance of the capacitor per unit area. Further, by forming the capacitor formation trench and an element formation trench that are formed in the surface of the semiconductor substrate by the same step, it is possible to simplify the manufacturing process. Whereas, a dielectric film of the capacitor in the capacitor formation region and a high-voltage gate insulating film in a MISFET formation region are formed by the same step; alternatively, the dielectric film of the capacitor in the capacitor formation region and a memory gate interlayer film between a polysilicon layer and a polysilicon layer in the memory cell formation region are formed by the same step.

Abstract: A two-step etch process is used to form a vertical collar oxide within the upper portion of a trench capacitor. The first step uses CF4/SiF4/O2 chemistry and ends when the bottom of the collar within the trench is opened although a thin oxide layer still remains on the surface of the PAD-nitride. The second etch step uses C4F8 chemistry to completely remove the remaining silicon oxide layer. The process provides a good uniformity in thickness of the PAD-nitride layer and sufficient collar oxide thickness in the very top section of the collar oxide. The process is applicable for manufacturing deep trench capacitors for DRAM devices.