Abstract: A method includes forming a first transistor having a first gate dielectric thickness and a first source/drain extension depth, a second transistor having a second gate dielectric thickness and the first source/drain extension depth, and a third transistor having the second gate dielectric thickness and a second source/drain extension depth. The second source/drain extension depth is greater than the first source/drain extension depth. The second gate dielectric thickness is greater than the first gate dielectric thickness. The first transistor is used in a logic circuit. The third transistor is used in an I/O circuit. The second transistor is made without extra processing steps and is better than either the first or third transistor for coupling a power supply terminal to the logic circuit in a power-up mode and decoupling the power supply terminal from the logic circuit in a power-down mode.

Abstract: A method includes forming a first transistor having a first gate dielectric thickness and a first source/drain extension depth, a second transistor having a second gate dielectric thickness and the first source/drain extension depth, and a third transistor having the second gate dielectric thickness and a second source/drain extension depth. The second source/drain extension depth is greater than the first source/drain extension depth. The second gate dielectric thickness is greater than the first gate dielectric thickness. The first transistor is used in a logic circuit. The third transistor is used in an I/O circuit. The second transistor is made without extra processing steps and is better than either the first or third transistor for coupling a power supply terminal to the logic circuit in a power-up mode and decoupling the power supply terminal from the logic circuit in a power-down mode.

Abstract: A semiconductor device includes a memory array of static-random-access memory cells. The SRAM cells are formed using a process flow more closely associated with logic-type devices. The SRAM cells are formed using one semiconductor layer compared to at least three typically seen with SRAM cells. The SRAM cells include many features that allow its dimensions to be scaled to very small dimensions (less than 0.25 microns and possible down to 0.1 microns or even smaller). A unique process integration scheme allows formation of local interconnects (522 and 524), wherein each local interconnect (522, 524) cross couples the inverters of the SRAM and is formed within a single opening (70). Also, interconnect portions (104) of word lines are laterally offset from silicon portions (36) of the same word line, so that the interconnect portions do not interfere with bit line connections.

Abstract: A semiconductor device and its method of fabrication are disclosed. The method includes forming a first well region in a semiconductor substrate. The semiconductor substrate includes a first doped region below the first well region. The first well region and the first doped region are doped with a first type dopant and the first well region is electrically connected to the first doped region. An isolation region is formed between the first well region and the first doped region. The isolation region is electrically connected to a second well region. The isolation region and the second well region are doped with a second dopant type The second dopant type is opposite the first dopant type. In one embodiment, the first type dopant includes a p-type dopant, and the second type dopant includes an n-type dopant. The method may further include, forming a second doped region within the first well region and below the isolation region.

Abstract: Electrical shorts and leakage paths are virtually eliminated by recessing conductive nodules (52) away from a conductor (72) or not forming the conductive nodules at all. In one embodiment, the refractory metal containing material (52) is recessed from the edge of the opening (32). When forming a nitride layer (54) within the opening (32), conductive nodules (52) are formed from a portion of the refractory metal containing material (20) such that the conductive nodules (52) lie within the recession (42). In another embodiment, an oxide layer (82, 102) is formed adjacent to the refractory metal containing material (20) before forming a nitride layer (84, 112).

Abstract: A semiconductor device includes a memory array of static-random-access memory cells. The SRAM cells are formed using a process flow more closely associated with logic-type devices. The SRAM cells are formed using one semiconductor layer compared to at least three typically seen with SRAM cells. The SRAM cells include many features that allow its dimensions to be scaled to very small dimensions (less than 0.25 microns and possible down to 0.1 microns or even smaller). A unique process integration scheme allows formation of local interconnects (522 and 524), wherein each local interconnect (522, 524) cross couples the inverters of the SRAM and is formed within a single opening (70). Also, interconnect portions (104) of word lines are laterally offset from silicon portions (36) of the same word line, so that the interconnect portions do not interfere with bit line connections.

Abstract: Electrical shorts and leakage paths are virtually eliminated by recessing conductive nodules (52) away from a conductor (72) or not forming the conductive nodules at all. In one embodiment, the refractory metal containing material (52) is recessed from the edge of the opening (32). When forming a nitride layer (54) within the opening (32), conductive nodules (52) are formed from a portion of the refractory metal containing material (20) such that the conductive modules (52) lie within the recession (42). In another embodiment, an oxide layer (82, 102) is formed adjacent to the refractory metal containing material (20) before forming a nitride layer (84, 112).

Abstract: EPROM cells include T-shaped floating gates (61, 171) and control gates that surround virtually all of the floating gates (61, 171) except for the portion of the floating gates (61, 171) that lie on a gate dielectric layer (51, 151). The EPROM cells may include customized well regions (22, 122) to allow flash erasing or individual cell erasing for electrically erasable EPROMs. Many different configurations of the memory cells are possible. The configurations of the source regions, drain regions, and well regions (22, 122) may be determined by how a user of the memory cells wants to program or erase the memory cells.

Abstract: EPROM cells include T-shaped floating gates (61, 171) and control gates that surround virtually all of the floating gates (61, 171) except for the portion of the floating gates (61, 171) that lie on a gate dielectric layer (51, 151). The EPROM cells may include customized well regions (22, 122) to allow flash erasing or individual cell erasing for electrically erasable EPROMs. Many different configurations of the memory cells are possible. The configurations of the source regions, drain regions, and well regions (22, 122) may be determined by how a user of the memory cells wants to program or erase the memory cells.

Abstract: A method for making a vertical profile contact opening (18) uses an etch stop layer (14), interposed between a conductor layer (10) and a dielectric layer (16), to eliminate resputtering of the underlying conductor material which prevents tapering of the etched opening (18). This contact opening formation is accomplished using different etchant chemistries, etching one film selective to the other. The use of the etch stop material in conjunction with conventional interconnect structures allows multiple stacking of contact features or multilevel interconnects to be achieved independent of underlying topography without increasing overall contact/via resistance. The method allows the fabrication of an unlanded via structure (30) having substantially vertical sidewall profile.

Abstract: An interconnect structure is formed having a substrate (10). A conductive layer (14) is formed overlying the substrate (10). A conductive layer (18) is formed overlying the conductive layer (14). An opening (19) is etched through the conductive layer (18), exposing a top portion of conductive layer (14), and forming a sidewall of the conductive layer (18). An selective isotropic etch procedure is used to laterally recess the sidewall of the conductive layer (18). A sidewall spacer (22) is formed adjacent the sidewall of the conductive layer (18). A conductive layer (24) is formed within opening (19) and adjacent the spacer (22) to form an interconnection between conductive layers (24 and 14). The interconnection is self-aligned, and conductive layer (18) is reliably isolated from the interconnect due to the lateral recessed sidewall of the conductive layer (18).

Abstract: A metal silicide interconnect (48, 92, 124) is formed in an integrated circuit using a sacrificial layer (30, 78, 108). In one embodiment a sacrificial layer of titanium nitride (30) is formed overlying a semiconductor substrate (12) and a polysilicon conductive member (20). The sacrificial titanium nitride layer (30) is then patterned and an underlying portion (40) of the semiconductor substrate (12), and a sidewall portion (42) of the polysilicon conductive member (20) are subsequently exposed. A metal layer (46) is deposited and then reacted with the exposed portion 40 of the semiconductor substrate (12) and the exposed sidewall (42) of the polysilicon conductive member (20) to form a metal silicide interconnect (48). The remaining portion of the sacrificial titanium nitride layer (38) is then removed after the metal silicide interconnect (48) has been formed without substantially altering the metal silicide interconnect (48).

Abstract: A contact between a heavily-doped region in the substrate and metal is made via a hole in a thick oxide layer and a polysilicon layer. The polysilicon layer is first etched to form a hole for establishing a mask for the eventual contact hole. Prior to forming the contact hole, a sidewall spacer of polysilicon is formed in the hole in the polysilicon layer. A thin oxide layer over the polysilicon layer is used for convenient end point detection during the formation of the polysilicon sidewall spacers. The sidewall spacer reduces the bore dimension of the hole in the polysilicon used for the mask for forming the contact hole. A hole is then etched in the thick oxide which is sloped and which has a bore dimension determined by the hole in the polysilicon which is reduced due to the sidewall spacer. The heavily-doped region, the contact hole, and the remaining polysilicon are coated with a barrier. The contact hole is then filled with a conductive material which also coats the barrier.

Abstract: A contact between a heavily-doped region in the substrate and metal is made via a hole in a thick oxide layer and a polysilicon layer. The polysilicon layer is first etched to form a hole for establishing a mask for the eventual contact hole. Prior to forming the contact hole, a sidewall spacer of polysilicon is formed in the hole in the polysilicon layer. A thin oxide layer over the polysilicon layer is used for convenient end point detection during the formation of the polysilicon sidewall spacers. The sidewall spacer reduces the bore dimension of the hole in the polysilicon used for the mask for forming the contact hole. A hole is then etched in the thick oxide which is sloped and which has a bore dimension determined by the hole in the polysilicon which is reduced due to the sidewall spacer. The heavily-doped region, the contact hole, and the remaining polysilicon are coated with a barrier. The contact hole is then filled with a conductive material which also coats the barrier.

Abstract: An interconnect structure is formed having a substrate (10). A conductive layer (14) is formed overlying the substrate (10). A conductive layer (18) is formed overlying the conductive layer (14). An opening (19) is etched through the conductive layer (18), exposing a top portion of conductive layer (14), and forming a sidewall of the conductive layer (18). An selective isotropic etch procedure is used to laterally recess the sidewall of the conductive layer (18). A sidewall spacer (22) is formed adjacent the sidewall of the conductive layer (18). A conductive layer (24) is formed within opening (19) and adjacent the spacer (22) to form an interconnection between conductive layers (24 and 14). The interconnection is self-aligned, and conductive layer (18) is reliably isolated from the interconnect due to the lateral recessed sidewall of the conductive layer (18).

Abstract: A semiconductor device and process wherein an ITLDD device (60) is formed having an inverse-T (IT) transistor gate with a variable work function (.PHI.) across the gate. The variable work function is attained by depositing a work function adjusting layer onto the thin gate extensions of the IT-gate. In accordance with one embodiment of the invention, a semiconductor substrate (10) of a first conductivity type is provided having a gate dielectric layer (12) formed thereon. First and second lightly doped regions (36, 37) of a second conductivity type are formed in the substrate which are spaced apart by a channel region (38). An IT-gate electrode (48) is formed on the gate dielectric layer overlying the first and second lightly doped regions and the channel region. The IT-gate has a relatively thick central section (32) and relatively thin lateral extensions (50) projecting from the central portion along the gate dielectric layer.

Abstract: Self-aligned and/or isolated contacts are formed in a semiconductor device, while simultaneously providing device planarization. In one form, an imagable material is deposited directly on a substrate material. The imagable material is patterned to form a sacrifical plug on a portion of the substrate material. A substantially planar insulating layer is then deposited overlying the substrate material. The plug formed of the imagable material is then removed, thereby exposing a portion of the substrate material and defining a contact opening. A conductive layer is deposited and patterned to complete formation of a contact.

Abstract: A semiconductor device and process wherein an ITLDD device (60) is formed having an inverse-T (IT) transistor gate with a variable work function (.PHI.) across the gate. The variable work function is attained by depositing a work function adjusting layer onto the thin gate extensions of the IT-gate. In accordance with one embodiment of the invention, a semiconductor substrate (10) of a first conductivity type is provided having a gate dielectric layer (12) formed thereon. First and second lightly doped regions (36, 37) of a second conductivity type are formed in the substrate which are spaced apart by a channel region (38). An IT-gate electrode (48) is formed on the gate dielectric layer overlying the first and second lightly doped regions and the channel region. The IT-gate has a relatively thick central section (32) and relatively thin lateral extensions (50) projecting from the central portion along the gate dielectric layer.

Abstract: The disclosed invention is a method for fabricating a multi-layer semiconductor device using selective planarization. In accordance with one embodiment of the invention, conductive members are formed on a substrate and a first insulating layer is deposited onto the substrate and the conductive members. A second insulating layer, which has a lower flow temperature than the flow temperature of the first layer, is deposited onto the first layer. A photoresist mask is patterned and developed to form a window which exposes an area between the conductive members. The device is preferentially etched such that only the exposed areas of the second insulating layer are removed, leaving the first insulating layer intact. An anisotropic etch is used to remove portions of the first insulating layer, leaving spacers along the edges of the conductive members. The photoresist mask is removed and a heating step is performed which flows the remaining portions of the second insulating layer, but not the first layer.

Abstract: A process for forming a feature on a substrate without etching into the surface of the substrate and causing recessed regions. A first layer of material is deposited to overlie the substrate and is formed of a different material to the substrate. The first layer is patterned, using conventional photolithography, to form windows in the first layer of material which expose a substrate surface. The etch selectively etches the first layer of material without substantially etching into the substrate material. A second layer of material, which is the same material as the substrate, is deposited to overlie the first layer of material and makes physical contact with the substrate through the windows patterned in the first layer. The second layer is blanket etched so that isolated regions are formed in regions defined by the windows patterned in the first layer.