Abstract: A method for forming a trench capacitor. A semiconductor substrate with a trench is provided, and a trench capacitor is formed in the trench with a storage node and a node dielectric layer. The top portion of the trench is ion implanted to a predetermined angle to form an ion doped area on a sidewall of the top portion of the trench and a top surface of the trench capacitor. The ion doped area is oxidized to form an oxide layer. A sidewall semiconductor layer is formed on another sidewall using the oxide layer as a mask, and then the oxide layer is removed. A barrier layer is conformally formed on the surface of the trench, and the trench is filled with a conducting layer.

Abstract: A semiconductor memory device includes first and second semiconductor layers, a buried insulating layer, a trench comprising a retreated portion, and the trench defining a first opening width at the second semiconductor layer, a first capacitor electrode formed in the first semiconductor layer, a capacitor insulating film formed in the trench, a second capacitor electrode formed in the trench in the first semiconductor layer, an insulating film formed on a side surface of the retreated portion and defining second and third opening widths, the second opening width serving as a width at the buried insulating layer and being not more than the first opening width, and the third opening width serving as a width at a boundary portion between the buried insulating layer and first semiconductor layer, and a connection portion electrically connected to the second capacitor electrode.

Abstract: A method for forming a bottle-shaped trench. A conductive layer surrounded by a doped layer is filled in a lower portion of a trench formed in a substrate. A doping region is formed in the substrate around the doped layer by a heat treatment. A collar silicon nitride layer is formed over an upper portion of the sidewall of the trench. The conductive layer and the doped layer are successively removed using the collar silicon nitride layer as a mask. The doping region is partially oxidized to form a doped oxide region thereon. The doped oxide region is removed to form a bottle-shaped trench. A conformable rugged polysilicon layer is formed in the lower portion of the bottle-shaped trench.

Abstract: A method of nitriding an insulation film, includes the steps of forming nitrogen radicals by high-frequency plasma, and causing nitridation in a surface of an insulation film containing therein oxygen, by supplying the nitrogen radicals to the surface of the insulation film.

Abstract: A method for forming a self-aligned buried strap in a vertical memory cell. A semiconductor substrate with a trench is provided, a capacitor wire is formed on the bottom portion of the trench, and a collar dielectric layer is formed between the capacitor wire and the semiconductor substrate to act as an isolation. The capacitor wire and the collar dielectric layer are etched to a predetermined depth, such that a gap is formed between the spacer and the capacitor wire and the collar dielectric layer. Ions are doped into the exposed semiconductor substrate to form an ion doped area acting as a buried strap. The spacer is removed, and an exposed collar dielectric layer is etched below the level of the surface of the capacitor wire, and a groove is formed between the capacitor wire and the trench sidewall to fill with a conducting layer.

Abstract: A method for fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected to the substrate on one side via a buried contact, using a hard mask with a corresponding mask opening.

Abstract: A method for fabricating a deep trench etched into a semiconductor substrate is provided by the present invention. The trench is divided into an upper portion and a lower portion and the method allows for the lower portion to be processed differently from the upper portion. After the trench is etched into the semiconductor substrate, a nitride layer is formed over a sidewall of the trench. A layer of oxide is then formed over the nitride layer. A filler material is then deposited and recessed to cover the oxide layer in the lower portion of the trench, followed by the removal of the oxide layer from the upper portion of the trench above the filler material. Once the oxide layer is removed from the upper portion of the trench, the filler material can also be removed, while allowing the oxide layer and the nitride layer to remain in the lower portion of the trench. Silicon is selectively deposited on the exposed nitride layer in the upper portion of the trench.

Abstract: A method and structure for increasing the threshold voltage of vertical semiconductor devices. The method comprises creating a deep trench in a substrate whose semiconductor material has an orientation plane perpendicular to the surface of the substrate. Then, vertical transistors are formed around and along the depth of the deep trench. Next, two shallow trench isolation are formed such that they sandwich the deep trench in an active region and the two shallow trench isolation regions abut the active region via planes perpendicular to the orientation plane. Then, the channel regions of the vertical transistors are exposed to the atmosphere in the deep trench and then chemically etched to planes parallel to the orientation plane. Then, a gate dielectric layer is formed on the wall of the deep trench. Finally, the deep trench is filled with poly-silicon to form the gate for the vertical transistors.

Abstract: A method of fabricating a deep trench capacitor is provided. A substrate with a deep trench thereon is provided. A bottom electrode is formed at a bottom of the deep trench and a capacitor dielectric layer, a first conductive layer, a protective layer and a collar layer are sequentially formed on the surface of the deep trench. The protective layer and the collar oxide layer on the surface of the first conductive layer are removed, material is deposited into the deep trench to form a material layer. A portion of the material layer is removed to form a first opening. Thereafter, collar oxide layer and the protective layer not covered by the material layer is removed. A portion of the mask layer and the protective layer on the sidewall of the first opening is removed to form a second opening. After removing the material layer, a second conductive layer and a third conductive layer are sequentially formed in the deep trench.

Abstract: A memory device that includes a semiconductor substrate, and an array of memory cells, each cell being electrically isolated from adjacent cells and including an island formed from the substrate, the island having a top portion and at least one sidewall portion, and being spaced apart from other islands by a bottom surface on the substrate, a capacitor formed contiguous with the sidewall portion, and a transistor formed on the top portion of the island, the transistor including a gate oxide layer formed on a surface of the top portion, a gate formed on the gate oxide layer, and a first and a second diffused regions formed in the top portion, the first diffused region being spaced apart from the second diffused region.

Abstract: A method of controlling the top width of a deep trench. A conductive layer is formed on the trench over a substrate of polysilicon with a recessed structure. An additional layer of amorphous silicon (?-Si) is deposited onto the polysilicon. After subsequent oxidation, the amorphous silicon is converted to SiO2. According to the invention, the top width of a deep trench is controlled, protecting bit lines from sub-threshold leakage.

Abstract: A method for removal of hemispherical grained silicon (HSG) in a deep trench is described. A buried silicon germanium (SiGe) layer serving as an etch stop layer is formed in the collar region of the trench, followed by depositing a HSG layer. The HSG layer is then successfully striped by wet etching with a potassium hydroxide/propanone/water etchant, that is, without damage to the trench sidewalls, since a good etch rate selectivity between the HSG layer and the SiGe layer is obtained by the wet etchant. In addition, no etch stop layer exists between the HSG layer and the bottom of the trench when manufacturing trench capacitors in accordance with the method; capacitance degradation is therefore not of concern.

Abstract: A method of forming a memory cell with a single sided buried strap. A collar oxide layer is formed on the sidewall of a trench. A conductive layer fills the trench. The conductive layer and the collar oxide layer are partially removed to form an opening having first and second sidewalls. The remaining collar oxide layer is lower than the remaining conductive layer. An angle implantation with F ions is performed on the first sidewall. A thermal oxidation process is performed to form a first oxide layer on the first sidewall and a second oxide layer on the second sidewall. The first oxide layer is thicker than the second oxide layer. The second oxide layer is removed to expose the second sidewall. A buried strap is formed at the bottom of the opening, insulated from the first sidewall by the first oxide layer.

Abstract: In one aspect, the invention provides a method of forming an electrical connection in an integrated circuitry device. According to one preferred implementation, a diffusion region is formed in semiconductive material. A conductive line is formed which is laterally spaced from the diffusion region. The conductive line is preferably formed relative to and within isolation oxide which separates substrate active areas. The conductive line is subsequently interconnected with the diffusion region. According to another preferred implementation, an oxide isolation grid is formed within semiconductive material. Conductive material is formed within the oxide isolation grid to form a conductive grid therein. Selected portions of the conductive grid are then removed to define interconnect lines within the oxide isolation grid. According to another preferred implementation, a plurality of oxide isolation regions are formed over a semiconductive substrate.

Abstract: A semiconductor Dynamic Random Access Memory (DRAM) cell is fabricated using a vertical access transistor and a storage capacitor formed in a vertical trench. A Shallow Trench Isolation (STI) region is used as a masking region to confine the channel region of the access transistor, the first and second output regions of the access transistor, and a strap region connecting the second output region to the storage capacitor, to a narrow portion of the trench. The so confined second output region of the access transistor has reduced leakage to similar second output regions of adjacent memory cells. Adjacent memory cells can then be placed closer to one another without an increase in leakage and cross-talk between adjacent memory cells.

Abstract: A semiconductor device ensuring an isolation of elements by a trench is provided. A method of manufacturing the semiconductor device includes the step of forming a silicon nitride film having an aperture, the step of selectively removing a part of a silicon substrate along aperture to form a recess defined by a side surface and a bottom surface in silicon substrate, the step of oxidizing the side surface and the bottom surface of the recess to form a thermal oxide film having a side portion and a bottom portion, and the step of selectively removing bottom portion of thermal oxide film and a part of silicon substrate by using silicon nitride film as a mask to form a trench.

Abstract: The present invention discloses a method for forming a semiconductor device which increases capacitance by forming a structure of a trench capacitor and uses an inner side face of the capacitor as a capacitor region.

Abstract: A method of forming a memory cell with a single sided buried strap. A collar oxide layer is formed on the sidewall of a trench. A conductive layer fills the trench. The conductive layer and the collar oxide layer are partially removed to form an opening having first and second sidewalls. The remaining collar oxide layer is lower than the remaining conductive layer. An angle implantation with F ions is performed on the first sidewall. A thermal oxidation process is performed to form a first oxide layer on the first sidewall and a second oxide layer on the second sidewall. The first oxide layer is thicker than the second oxide layer. The second oxide layer is removed to expose the second sidewall. A buried strap is formed at the bottom of the opening, insulated from the first sidewall by the first oxide layer.

Abstract: A first insulating layer is formed on semiconductor substrate, and a trench is formed in the first insulating layer. An amorphous silicon layer doped with impurities is formed on a side and bottom walls of the trench. Next, a resist material is partially filled in the trench so that an upper portion of the amorphous silicon layer is exposed. The exposed portion is implanted with impurity ions. After removal of the resist material, the amorphous silicon layer is heat treated so as to grow hemispherical grains on its surface.

Abstract: A trench capacitor, in particular for use in a semiconductor memory cell, has a trench formed in a substrate; an insulation collar formed in an upper region of the trench; an optional buried plate in the substrate region serving as a first capacitor plate; a dielectric layer lining the lower region of the trench and the insulation collar as a capacitor dielectric; a conductive second filling material filled into the trench as a second capacitor plate; and a buried contact underneath the surface of the substrate. The substrate has, underneath its surface in the region of the buried contact, a doped region introduced by implantation, plasma doping and/or vapor phase deposition. A tunnel layer, in particular an oxide, nitride or oxinitride layer, is preferably formed at the interface of the buried contact. A method for producing a trench capacitor is also provided.

Abstract: A dynamic random access memory (DRAM) structure and a fabricating process thereof are provided. In the fabricating process, a channel region is formed with a doped region having identical conductivity as the substrate in a section adjacent to an isolation structure. The doped region is formed in a self-aligned process by conducting a tilt implantation implanting ions into the substrate through the upper portion of the capacitor trench adjacent to the channel region after forming the trench but before the definition of the active region.

Abstract: A method for enhancing the on-current carrying capability of a MOSFET device is disclosed. In an explanary embodiment, the method includes recessing fill material formed within a shallow trench isolation (STI) adjacent the MOSFET so as to expose a desired depth of a sidewall of the STI, thereby increasing the effective size of a parasitic corner device of the MOSFET. The threshold voltage of the parasitic corner device is then adjusted so as to substantially equivalent to the threshold voltage of the MOSFET device.

Abstract: A collar dielectric process for reducing a top width of a deep trench. A semiconductor silicon substrate has a deep trench and a deep trench capacitor. The deep trench capacitor has a node dielectric formed on the sidewall and bottom of the deep trench, and a storage node formed in the deep trench and reaching a predetermined depth. An ion implantation process is performed to form an ion implantation area on the substrate at the top of the deep trench. Then, the node dielectric is removed until the top of the node dielectric is leveled off with the top of the storage node, thus exposing the sidewall of the deep trench outside the deep trench capacitor. Next, an oxidation process is performed to grow a first silicon oxide layer on the exposed sidewall of the deep trench, in which the first silicon layer is outside the ion implantation area.

Abstract: A method for forming a vertical transistor and a trench capacitor. A semiconductor substrate having a pad stacked layer on the surface and a trench formed therein is provided. A capacitor is formed at the bottom part of the trench and a portion of the upper sidewall of the trench is exposed. A conductive wire is then formed on the capacitor, followed by forming a dielectric layer on the exposed sidewalls of the trench. A trench top dielectric is then formed by liquid phase deposition on the conductive wire. A transistor is then formed on the trench top dielectric, which isolates the transistor from the capacitor.

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: A method for forming a vertical transistor and a trench capacitor. A semiconductor substrate having a pad stacked layer on the surface and a trench formed therein is provided. A capacitor is formed at the bottom part of the trench and a portion of the upper sidewall of the trench is exposed. A conductive wire is then formed on the capacitor, followed by forming a dielectric layer on the exposed sidewalls of the trench. A trench top dielectric is then formed by liquid phase deposition on the conductive wire. A transistor is then formed on the trench top dielectric, which isolates the transistor from the capacitor.

Abstract: A method for fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected to the substrate on one side via a buried contact, using a hard mask with a corresponding mask opening.

Abstract: The invention provides a trench storage structure that includes a substrate having a trench, a capacitor conductor in the lower part of the trench, a conductive node strap in the trench adjacent the capacitor conductor, a trench top oxide above the capacitor conductor, and a conductive buried strap in the substrate adjacent the trench top oxide.

Abstract: A 3D microelectronic structure is provided which includes a substrate having at least one opening present therein, the at least one opening having sidewalls which extend to a common bottom wall; and a thermal nitride layer present on at least an upper portion of each sidewall of openings. A method for fabricating the above-mentioned 3D microelectronic structure is also provided. Specifically, the method includes a step of selectively forming a thermal nitride layer on at least an upper portion of each sidewall of an opening formed in a substrate.

Abstract: A semiconductor memory device includes first and second semiconductor layers, a buried insulating layer, a trench comprising a retreated portion, and the trench defining a first opening width at the second semiconductor layer, a first capacitor electrode formed in the first semiconductor layer, a capacitor insulating film formed in the trench, a second capacitor electrode formed in the trench in the first semiconductor layer, an insulating film formed on a side surface of the retreated portion and defining second and third opening widths, the second opening width serving as a width at the buried insulating layer and being not more than the first opening width, and the third opening width serving as a width at a boundary portion between the buried insulating layer and first semiconductor layer, and a connection portion electrically connected to the second capacitor electrode.

Abstract: In a process of fabricating a narrow channel width PMOSFET device, the improvement of affecting reduction of negative bias temperature instability by use of F2 side wall implantation, comprising: a) forming a shallow trench isolation (STI) region in a substrate; b) forming a gate on a gate oxide in the substrate; c) forming a liner layer in said shallow trench isolation region and subjecting the liner layer to oxidation to form a STI liner oxidation layer; d) implanting F2 into side walls of the STI liner oxidation layer at a large tilted angle in sufficient amounts to affect reduction of negative bias temperature instability after a high density plasma fill of the STI F2 implanted liner oxidation layer; and e) filling the STI F2 implanted structure from step d) with a high density plasma (HDP) fill to affect reduction of negative bias temperature instability.

Abstract: A semiconductor memory having memory cells, each memory cell includes a selection transistor and a trench capacitor. The selection transistor is formed in the form of a vertical transistor. In such a case, two word lines are separated only by a connecting channel that enables an electrically conductive connection between a trench filling of the trench capacitor and a bit line.

Abstract: Methods of forming a channel region between isolation regions of an integrated circuit substrate are disclosed. In particular, a mask can be formed on an isolation region that extends onto a portion of the substrate adjacent to the isolation region to provide a shielded portion of the substrate adjacent to the isolation region and an exposed portion of the substrate spaced apart from the isolation region having the shielded portion therebetween. A channel region can be formed in the exposed portion of the substrate. Related integrated circuits are also discussed.

Abstract: A semiconductor device comprises a first conductor formed inside or on the top surface of a semiconductor substrate; an insulating film formed on the top surface of said semiconductor substrate or on the top surface of said first conductor; contact holes penetrating said insulating layer to reach said first conductor; a second conductor filled inside said contact holes and electrically connected to said first conductor; and an interconnection extending across contact regions on a top surface region of said insulating layer where said contact holes are formed respectively, and having opposite sides at least one of which is in contact with said second conductor inside said contact regions.

Abstract: The present invention relates to a method for forming an isolation film for semiconductor devices.

Abstract: In fabricating a shallow trench isolation (STI), a silicon oxide layer, a silicon nitride layer and a moat pattern is sequentially deposited on a silicon substrate. Next, the silicon nitride layer and the silicon oxide layer is etched using the moat pattern as a mask to thereby partially expose the silicon substrate and then the moat pattern is removed. Ion implanting process is performed into the silicon substrate using the silicon nitride layer as a mask, adjusting a dose of an implanted ion and an implant energy, to thereby form an isolation region. And then, the isolation region to form a porous silicon and to form an air gap in the porous silicon is anodized, wherein a porosity of the porous silicon is determined by the dose of the implanted ion. Next, the porous silicon is oxidized through an oxidation process. Finally, the silicon nitride layer is removed.

Abstract: Forming a vertical MOS transistor or making another three-dimensional integrated circuit structure in a silicon wafer exposes planes having at least two different crystallographic orientations. Growing oxide on different crystal planes is inherently at different growth rates because the inter-atomic spacing is different in the different planes. Heating the silicon in a nitrogen-containing ambient to form a thin layer of nitride and then growing the oxide through the thin nitrided layer reduces the difference in oxide thickness to less than 1%.

Abstract: A dynamic random access memory cell comprising: a trench capacitor formed in a silicon substrate; a vertical MOSFET formed in a silicon substrate above the trench capacitor, the vertical MOSFET having a gate electrode, a first source/drain region extending from a surface of the silicon substrate into the silicon substrate, a buried second source/drain region electrically contacting the trench capacitor, a channel region formed in the silicon substrate between the first source/drain region and the buried second source/drain region and a gate oxide layer disposed between the gate electrode and the channel region; the first source/drain region also belonging to an adjacent vertical MOSFET, the adjacent vertical MOSFET having a buried third source/drain region electrically connected to an adjacent trench capacitor, the buried second and third source/drain regions extending toward one another; and a punch through prevention region disposed between the buried second and third source/drain regions.

Abstract: Method for forming buried plates. The method includes providing a substrate formed with a pad stacked layer on the surface, a bottle trench and a protective layer on the upper sidewalls of the bottle trench, forming a doped hemispherical silicon grain (HSG) layer on the protective layer and the sidewalls and bottom of the bottle trench, removing the hemispherical silicon grain layer on the protective layer without removing the hemispherical silicon grain layer from the lower sidewalls and bottom of the bottle trench, forming a covering layer on the protective layer, and subjecting the doped hemispherical silicon grain layer to drive-in annealing so that ions in the HSG layer diffuse out to the substrate, thereby forming a buried plate within the lower sidewalls of the bottle trench.

Abstract: A DRAM cell with a vertical transistor forms a buried strap outdiffusion with reduced lateral extent by shifting high temperature steps that affect the thermal budget before the initial buried strap diffusion. The gate conductor is formed in two steps, with poly sidewalls being put down above a sacrificial Trench top oxide to form a self-aligned poly-gate insulator structure before the formation of the LDD extension.

Abstract: There is provided a method of manufacturing a vertical semiconductor device including a structural section in which an n−-type semiconductor region and a p−-type semiconductor region are arranged alternately without filling trenches by epitaxial growth. A p−-type silicon layer (13) which becomes a p−-type semiconductor region (12) is formed. An n−-type semiconductor region (11) is formed by diffusing n-type impurities into the p−-type silicon layer (13) through the sidewalls of first trenches (22) formed in the p−-type silicon layer (13).

Abstract: In a method for forming a trench capacitor a first layer of silicon oxide is deposited in a storage trench and a layer of silicon is deposited over the first layer by a chemical vapor deposition process. A layer of an oxidizable metal is deposited over the layer of silicon. The layer of silicon and the layer of the oxidizable metal are subsequently oxidized to form a layer of silicon oxide and metal oxide.

Abstract: The invention includes a method of forming a capacitor electrode. A sacrificial material sidewall is provided to extend at least partially around an opening. A first silicon-containing material is formed within the opening to partially fill the opening, and is doped with conductivity-enhancing dopant. A second silicon-containing material is formed within the partially filled opening, and is provided to be less heavily doped with conductivity-enhancing dopant than is the first silicon-containing material. At least some of the second silicon-containing material is converted into hemispherical grain silicon, and at least some of the sacrificial material sidewall is removed. The invention also encompasses methods of forming capacitors and capacitor assemblies incorporating the above-described capacitor electrode. Further, the invention encompasses capacitor assemblies and capacitor structures.

Abstract: The novel trench capacitors have a constant or increased capacitance. Materials for a second electrode region and if appropriate a first electrode region include a metallic material, a metal nitride, or the like, and/or a dielectric region is formed with a material with an increased dielectric constant. An insulation region is formed in the upper wall region of the trench after the first electrode region or the second electrode region has been formed, by selective and local oxidation.

Abstract: Disclosed is a method for fabricating a capacitor in a semiconductor device. A semiconductor substrate is provided. A bottom electrode is formed on the substrate by sequentially depositing Ru through a PECVD process and Ru through a LPCVD process on the semiconductor substrate. A Ta2O5 dielectric layer is formed on the bottom electrode and forming a top electrode on the Ta2O5 dielectric layer.

Abstract: A method for fabricating DRAM and flash memory cells on a single chip includes providing a silicon substrate, forming a trench capacitor for each of the DRAM cells in the silicon substrate, forming isolation regions in the silicon substrate which are electrically isolated from each other, forming first type wells for DRAM and flash memory cells at first predetermined regions of the silicon substrate by implanting a first type impurity in the first predetermined regions, forming second type wells for DRAM and flash memory cells at second predetermined regions in the first type wells by implanting a second type impurity in the second predetermined regions, forming oxide layers for DRAM and flash memory cells on the second type wells, forming gate electrodes for DRAM and flash memory cells on the oxide layers for DRAM and flash memory cells, and forming source and drain regions for DRAM and flash memory cells in the respective second type wells for DRAM and flash memory cells, in which the source and drain regio

Abstract: In a method of forming a DRAM cell in a semiconductor substrate, the improvement of maintaining a substantially full trench opening during trench processing comprising: a) forming a pad nitride on the surface of the substrate and reactive ion etching (RIE) a trench vertically to a first depth; b) depositing a nitride layer in the trench; c) filling the trench with a poly silicon fill; d) recess etching the fill to the collar depth; e) oxidizing to transform the exposed nitride layer into a nitrided oxide collar or depositing an oxide on the layer of nitride; f) reactive ion etching to open the bottom oxide; g) stripping the poly fill trench, and performing a nitride etch selective to oxide; h) expanding the trench horizontally by etching lower trench sidewalls and bottom while masking the upper sidewalls; i) forming a buried plate at the bottom of the trench sidewalls; j) forming the node dielectric in the deep trench to grow a collar oxide that consists of a nitrided oxide and a layer of node nitride; k) fil

Abstract: It is proposed when forming field-effect transistor devices in a semiconductor substrate for the overlapping region of a source-drain region that is to be provided to be formed directly as a material region, in particular with outdiffusion processes being avoided to the greatest extent. This takes place in particular by forming the connection region or buried-strap region as selectively epitaxially grown-on single-crystal, possibly doped silicon.

Abstract: A method for reducing damage to a semiconductor structure resulting from migration of constituents of a first component part (3) of the structure into a subsequently deposited second component part (8) of the structure which makes contact with a surface of the first component part (3). A third component part (10) of the structure is deposited before the second component part (8), the third component part (10) being positioned so as to be contacted by the second component part (8) adjacent the said surface of the first component part (3). The third component part (10) has a composition such that it acts as a donor of constituents (12) to the second component part. The donor constituents (12) migrate into the second component part (8) when the second component part (8) is deposited and reduce the migration of constituents (11) of the first component part (3) into the second component part (8). If the first component part (3) is silicon, the third component part (10) may be polysilicon.

Abstract: A method for producing a semiconductor device having a first region with storage capacitors and a second region with at least one well surrounded by an insulation. The method creates both the storage capacitors and the insulation by forming trenches in the first region and at least one trench in the second region, and the trenches have a depth of at least 2 &mgr;m. The trenches in the first region are treated to provide first and second electrodes separated by a dielectric to form the capacitors and each trench in the second region provides an insulation which surrounds any wells in the second region.