Abstract: Two different gate conductor dielectric caps are used in the array and support device regions so that the bitline contact can be fabricated in the array region, but a thinner hard mask can be used for better linewidth control in the support device region. The thinner dielectric cap is made into dielectric spacers in the array device regions during support mask etching. These dielectric spacers allow for the array gate conductor resist line to be made-smaller than the final gate conductor linewidth. This widens the array gate conductor processing window. The second dielectric cap layer improves linewidth control for the support devices and the array devices. Two separate gate conductor lithography steps and gate conductor dielectric etches are carried out in the present invention to optimize the gate conductor linewidth control in the array and support device regions. The gate conductors in the array and support devices regions are etched simultaneously to reduce production cost.

Abstract: A memory device structure is provided in which the array oxide layer has a thickness that is greater than the thickness of the support oxide layer.

Abstract: A memory device structure is provided in which the array oxide layer has a thickness that is greater than the thickness of the support oxide layer.

Abstract: A method for making a semiconductor device, includes forming an oxide layer on a silicon substrate, forming a nitride layer over the oxide layer; depositing one of a doped oxide layer and an undoped porous oxide layer on the nitride layer, etching trenches through the one of the doped layer and the undoped porous oxide layer, the nitride layer, and the oxide layer, depositing an undoped oxide layer to fill the trenches, and patterning the undoped oxide by chemical mechanical polishing (CMP).

Abstract: According to the present invention, a method for fabricating vertical circuit devices which include a body contact is disclosed. During the fabrication process, the body of a transistor is formed from a pillar of single crystal silicon. The silicon pillar is formed over a butted junction of N+ and P+ diffusions. This fabrication process results in a pillar structure which has an n+ diffusion contacting a portion of the base of the transistor body and a P+ diffusion contacting the remainder of the base of the transistor body. The proportion of N+ and P+ area at the base of the silicon pillar depends on the overlay of the opening to the butted junction. Gate oxide is grown over the entire pillar and a polysilicon gate material is then deposited and etched to form the transistor gate. Metal contact studs are formed, preferably via deposition. After fabrication, the entire surface of the device can be planarized by using any standard Chemical Mechanical Planarization (CMP) process.

Abstract: A method of forming a semiconductor device, including forming a substrate with a memory array region and a logic device region, growing a thick gate dielectric over the substrate, forming a gate stack, including a first polysilicon layer, over the thick gate dielectric for the memory array region, forming a thin gate dielectric on the substrate over the logic device region, wherein layers of the gate stack in the memory array region protect the thick gate oxide during the forming of the thin gate dielectric, forming a second polysilicon layer for the gate stack in the logic device region, to produce a resulting structure, wherein a thickness of the second polysilicon layer is at least as thick as the gate stack in the memory array region, planarizing the structure using chemical mechanical polishing (CMP), and patterning the gate stacks in said memory array region and the logic device region.

Abstract: A semiconductor MOSFET device is formed on a silicon substrate which includes trenches filled with Shallow Trench Isolation dielectric trench fill structures and extending above the surface of the substrate. The trench fill structures have protruding sidewalls with channel regions in the substrate having corner regions adjacent to the trench fill structures. The channel regions are between and adjacent to the STI trench fill structures doped with one concentration of dopant in the centers of the channel regions with a higher concentration of dopant in the corner regions. The dopant concentration differential provides a substantially equal concentration of electrons in the centers and at the corner regions of the channel regions.

Abstract: According to the present invention, a method for fabricating vertical circuit devices which include a body contact is disclosed. During the fabrication process, the body of a transistor is formed from a pillar of single crystal silicon. The silicon pillar is formed over a butted junction of N+ and P+ diffusions. This fabrication process results in a pillar structure which has an n+ diffusion contacting a portion of the base of the transistor body and a P+ diffusion contacting the remainder of the base of the transistor body. The proportion of N+ and P+ area at the base of the silicon pillar depends on the overlay of the opening to the butted junction. Gate oxide is grown over the entire pillar and a polysilicon gate material is then deposited and etched to form the transistor gate. Metal contact studs are formed, preferably via deposition. After fabrication, the entire surface of the device can be planarized by using any standard Chemical Mechanical Planarization (CMP) process.

Abstract: A process for the low temperature deposition of a thin film of borophosphosilicate glass ("BPSG") for use in semiconductor devices, such as DRAMs, is disclosed. The process includes utilizing R--OH groups as reagents to provide additional --OH groups so that an intermediate {Si(OH).sub.4 }.sub.n is formed having superior reflow properties so that the annealing and reflow steps may occur at temperatures less than 750.degree. C., which is the current processing temperature.

Abstract: A composite dielectric material useful in advanced memory applications such as dynamic random access memory (DRAM) cells is provided. The composite dielectric material of the present invention includes a mixed oxide such as TiO.sub.2 or Ta.sub.2 O.sub.5 that is interdiffused into a Si.sub.3 N.sub.4 film. Capacitors including the composite dielectric material of the present invention are also disclosed.

Abstract: Significant amounts of pattern distortion were found to be the result of reflowing borophosphosilicate glass (BPSG) and silicon dioxide shrinkage during high temperature junction anneals. In order to remedy this problem, a method for suppressing the pattern distortion by subjecting the wafer coated with BPSG and with silicon dioxide layers to a high temperature anneal before patterning is disclosed. The high temperature anneal densities the undoped silicon dioxide before patterning, so that shrinkage of the undoped silicon dioxide does not affect the patterning steps.

Abstract: A semiconductor MOSFET device is formed on a silicon substrate which includes trenches filled with Shallow Trench Isolation dielectric trench fill structures and extending above the surface of the substrate. The trench fill structures have protruding sidewalls with channel regions in the substrate having corner regions adjacent to the trench fill structures. The channel regions are between and adjacent to the STI trench fill structures doped with one concentration of dopant in the centers of the channel regions with a higher concentration of dopant in the corner regions. The dopant concentration differential provides a substantially equal concentration of electrons in the centers and at the corner regions of the channel regions.

Abstract: Significant amounts of pattern distortion were found to be the result of reflowing borophosphosilicate glass (BPSG) and silicon dioxide shrinkage during high temperature junction anneals. In order to remedy this problem, a method for suppressing the pattern distortion by subjecting the wafer coated with BPSG and with silicon dioxide layers to a high temperature anneal before patterning is disclosed. The high temperature anneal densifies the undoped silicon dioxide before patterning, so that shrinkage of the undoped silicon dioxide does not affect the patterning steps.

Abstract: A number of methods to prevent divot formation, and the resulting enhanced electric field associated therewith, are disclosed. In a first embodiment of the present invention, spacers having a low etch rate in hydrofluoric acid solution, and that can be etched selectively to silicon dioxide are used to protect the silicon nitride liner from forming the divot. In a second embodiment of the present invention, a silicon dioxide spacer is used prior to the etching of the trenches, to allow the formation of the divots above the level of the silicon wafer, where they are not problematic. In a third embodiment of the present invention, a multi layer polish stop is used to prevent the formation of the divot.

Abstract: The present invention provides a method for fabricating tungsten local interconnections in high density CMOS circuits, and also provides high density CMOS circuits having local interconnections formed of tungsten. Pursuant to the method, an etch stop layer of chromium is initially deposited on the circuit elements of the CMOS silicon substrate. Next, a conductive layer of tungsten is non-selectively deposited on the chromium layer. A photoresist mask is then lithographically patterned over the tungsten layer. The tungsten layer is then etched down to, and stopping at, the chromium layer, after which the photoresist mask is stripped. The stripping preferably uses a low temperature plasma etch in O.sub.2 at a temperature of less than 100.degree. C. Finally, a directional O.sub.2 reactive ion etch is used to remove the chromium layer selectively to the silicon substrate. Borderless contacts are formed with the aid of the chromium etch stop layer beneath the tungsten local interconnection layer.

Abstract: A method of fabricating a dielectric material useful in advanced memory applications which comprises a metal oxide such as TiO.sub.2 or Ta.sub.2 O.sub.5 interdiffused into a Si.sub.3 N.sub.4 film is provided.

Abstract: A method of forming interlevel studs of at least two different materials in an insulating layer on a semiconductor wafer. After forming an insulating layer of BPSG on a Front End of the Line (FEOL) structure, the BPSG layer is chem-mech polished. Vias are formed through the BPSG layer in array areas. A thin doped poly layer is deposited on the surface of the BPSG layer. The structure is annealed and vias are formed in support areas. Dopants are implanted into support areas through the vias. After annealing to diffuse implanted dopant, a metal layer is formed on the poly layer. Then, the structure is chem-mech polished back to the poly layer. A final chem-mech polish step removes the poly layer, leaving metal studs in the support areas and poly-lined metal cored studs in the array areas.

Abstract: A borderless contact method for a semiconductor device is disclosed employing a disposable etch stopping spacer to protect the upper edges of adjacent structure during contact hole etching. An exemplary FET gate structure is formed on a substrate adjacent to a source or drain diffusion region. A layer of dielectric material is deposited over the structure including the gate stack. An etch stopping spacer, of a material selectively etchable relative to the dielectric material is placed upon the sidewalls and the upper edges of the gate stack.The resulting structure is blanketed with a glass layer which is selectively masked and etched to provide a hole for making a borderless contact to the substrate adjacent to the gate stack. The spacer itself can be etched away prior to filling the hole with contact material in order to maximize the contact area.