Abstract: A method for processing a conductive layer, such as a doped polysilicon layer (14) of a gate stack, provides a degas step after precleaning to reduce particle count and defectivity. The conductive layer is provided on a substrate (10), e.g., a silicon wafer. The substrate (10) and conductive layer are subjected to an elevated temperature, under a vacuum, whereby certain species are liberated. The substrate having the conductive layer formed thereon is then removed from the chamber, and moved to a second, separate chamber, in which a second conductive layer (20) is deposited. By switching chambers, the liberated species are largely prevented from contributing to particle count at the interface between the conductive layers. Alternatively, the second conductive layer is formed in the same chamber, provided that the liberated species are removed from the chamber prior to deposition of the second conductive layer.

Abstract: A metal-semiconductor layer (26) is formed over an insulating layer (20) such that the metal-semiconductor layer (26) is graded to have varying amounts of the semiconductor and metal throughout the layer. In one embodiment, the metal-semiconductor layer (26) has relatively higher silicon content near the layer's lower and upper surfaces. At the midpoint, the layer is close to stoichiometric tungsten silicide. In another embodiment, a metal-semiconductor-nitrogen layer is formed having nitrogen nearer the lower surface and essentially no nitrogen near the upper surface. The layer (26) can be formed using chemical vapor deposition or sputtering.

Abstract: A shared contact structure (30) is formed to electrically connect three coupling layers (59,60,46) to each other and to an active region (33) in a semiconductor substrate (31). A first coupling layer (59) and a second coupling layer (60) are formed such that they are physically isolated from each other. The second coupling layer (60) is formed such that it is in physical contact with the active region (33). A contact opening (45) is formed, which exposes a portion of coupling layers (59, 60). The third coupling layer (46) is then formed so that it is in electrical contact with the second coupling layer (60) and the first coupling layer (59).

Abstract: A semiconductor device (10) is formed having an SRAM array with a plurality of SRAM cells. In forming the access and latch transistors, two different gate electrode compositions are used to form the access and latch transistors. More specifically, a dielectric layer (22) is formed between two conductive layers (26 and 28) within the gate electrode (52) for the access transistors while the dielectric layer is not formed between the two conductive layers (26 and 28) for the latch transistors. This structure allows an increase in the beta ratio for the SRAM cell thereby making a more stable SRAM cell without having to use diffused resistors between the access transistors in storage nodes or by having to form a differential thickness between the gate dielectric layers for the latch transistors and the access transistors.

Abstract: A process for fabricating an MOS device (44) having a segmented channel region (48) includes the fabrication of a compound MOS gate electrode (46). Both the segmented channel region (48) and the MOS gate electrode (46) are formed by creating an opening (18) and an insulating layer (16) overlying a first polycrystalline silicon layer (14). The lateral extent of both the MOS gate electrode (46) and a buried junction region (24) formed in the semiconductor substrate (10) are defined by first sidewall spacer (22) and a second sidewall spacer (32) formed adjacent to the first sidewall spacer (22).

Abstract: A process for polish planarizing a fill material (40) overlying a semiconductor substrate (30) includes a multi-step polishing process. In one embodiment, a second planarization layer (42) is deposited over a fill material (40) and a portion of the fill material (40) is removed leaving a remaining portion (44). The pad pressure of a CMP apparatus (20) is adjusted such that a first pressure is generated during the polishing process. Then, the remaining portion (44) is removed, while operating the CMP apparatus (20) at a second pad pressure. The selectivity of the polishing process is maintained by reducing the pad pressure during the second polishing step. In a second embodiment, after the first polishing step is performed, the remaining portion (44) is removed by an etching process using a portion (46) of second planarization layer (42).

Abstract: Vertically stacked regions of n-type and p-type conductivity are formed around bipolar and field effect transistors to reduce parasitic capacitance between the semiconductor device and surrounding well regions. Under reverse bias a portion of the vertically stacked region is fully depleted and thus reduces the parasitic capacitance between the semiconductor device and the well region.

Abstract: A thin-film transistor and SRAM memory cell include thin-film source and drain regions (12, 14) separated by an opening (22) and overlying and insulating layer (11). A thin-film channel layer (16) overlies the thin-film source and drain regions (12, 14) and a portion of the insulating layer (11) exposed by the opening (22). A thin-film gate electrode (20) is positioned in the opening (22) and defines a thin-film channel region (24) in the thin-film channel layer (16). The thin-film gate electrode (20) is separated from the thin-film channel region (24) by a gate dielectric layer (18). The thin-film channel region (24) extends along vertical wall surfaces (26, 28) of the thin-film source and drain regions (12, 14) providing an extended channel length for the thin-film transistor.

Abstract: An under-gated thin film transistor (54) having low leakage current and a high on/off current ratio is formed using a composite layer (40) of semiconducting material. In one embodiment a composite layer (40) of semiconducting layer is formed by depositing two distinct layers (34, 38) of semiconducting material over the transistor gate electrode (18). The composite layer (40) is then patterned and implanted with ions to form a source region (46) and a drain region (48) within the composite layer (40), and to define a channel region (50) and an offset drain region (52) within the composite layer (40).

Abstract: An under-gated thin film transistor (54) having low leakage current and a high on/off current ratio is formed using a composite layer (40) of semiconducting material. In one embodiment a composite layer (40) of semiconducting layer is formed by depositing two distinct layers (34, 38) of semiconducting material over the transistor gate electrode (18). The composite layer (40) is then patterned and implanted with ions to form a source region (46) and a drain region (48) within the composite layer (40), and to define a channel region (50) and an offset drain region (52) within the composite layer (40).

Abstract: Vertically stacked regions of n-type and p-type conductivity are formed around bipolar and field effect transistors to reduce parasitic capacitance between the semiconductor device and surrounding well regions. Under reverse bias a portion of the vertically stacked region is fully depleted and thus reduces the parasitic capacitance between the semiconductor device and the well region.

Abstract: A semiconductor device (10) has a capacitor structure formed within an opening (30) of a stack of a dielectric layer (24), a conductive layer (26), and a dielectric layer (28). A first capacitor electrode is formed by conductive sidewall spacers (32) which are in electrical contact with conductive layer (26) along sidewalls of the opening. A capacitor dielectric (34) is formed on the sidewall spacers. A second capacitor electrode is formed by a conductive layer (38), either alone or in conjunction with a second set of conductive sidewall spacers (36). In one embodiment, the capacitor is formed over a gate electrode (15) of a bulk transistor and makes contact thereto. The capacitor structure is particularly suited for use in an SRAM cell.

Abstract: The present invention includes an integrated circuit having a self-aligned contact that makes contact to both a region within the substrate and a capacitor plate of a capacitor that is adjacent to the doped region. The present invention also includes a static-random-access memory cell with a capacitor having a first plate and a second plate. The first plate includes a first plate section of a gate electrode of a transistor, and the second plate includes a first conductive member that is substantially coincident with the first plate section. The second plate may be formed over a gate electrode of a latch transistor or over a word line. The disclosure includes methods of forming the integrated circuit and the static-random-access memory cell.

Abstract: An SRAM cell is formed such that pass channel-stop regions, which are adjacent to the pass transistors, have a higher doping concentration compared to the latch channel-stop regions that are adjacent to the latch transistors. In one embodiment, the pass channel-stop regions are formed using two channel-stop doping steps, whereas the latch channel-stop regions are formed during only one channel-stop doping step. The doping steps may be performed before or after field isolation is formed. The higher doping concentration causes the dopant from the pass channel-stop regions to extend laterally further from the edge of the field isolation compared to the latch channel-stop regions. The process can be adapted for use in almost any type of field isolation process.

Abstract: A semiconductor memory cell (10) includes first and second cross-coupled driver transistors (13, 19) each having a source-drain region and a channel region formed in a first thin-film layer (36, 36'). First and second parallel opposed wordlines (20, 22) overlie a single-crystal semiconductor substrate (12) and the channel region (46) of each driver transistor overlies a portion of an adjacent wordline. A portion of the thin-film layer (36, 36') makes contact to the single-crystal semiconductor substrate (12) adjacent to the opposite wordline. The channel and source-drain regions of first and second load transistors (15, 21) are formed in a second thin-film layer (64) which overlies the driver transistors (13, 19). The load transistors (15, 21) are cross-coupled to the driver transistors (13, 19) through common nodes (31, 33).

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: A semiconductor device (10) has a thin-film transistor (TFT) formed in and around an opening (24) in a dielectric layer (22). A conductive layer (26) lines the opening sidewalls and serves as a gate electrode of the transistor. A conductive layer (30) is deposited over the gate electrode to form a source region (32), a channel region (36), and a drain region (34). The two conductive layers are separated by a gate dielectric (28). Because both the gate electrode and the channel region conform to the opening sidewalls and bottom, the entire channel region is under direct gate control. Device (10) may also include a conductive region, such as a gate electrode (15) of a bulk transistor, at the bottom of opening (24) and in electrical contact with the TFT gate electrode.

Abstract: A transistor structure (10) has a substrate (12). A first transistor is formed within the substrate (12) having a source region (38), a drain region (30), and a gate electrode formed by a first spacer (26a). A second transistor is formed within the substrate (12) by the source region (38), a drain region (28), and a gate electrode formed by a second spacer (26a). A third transistor is formed overlying the first transistor. The third transistor has a source region (34a), a drain region (34c), a channel region (34b), and a gate electrode formed by the first spacer (26a). A fourth transistor is formed overlying the second transistor. The fourth transistor has a source region (34a), a drain region (34c), a channel region (34b), and a gate electrode formed by the second spacer (26a). The first, second, third, and fourth transistors may be interconnected to form a portion of a compact static random access memory (SRAM) cell.

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 method is provided for the formation of ultra-shallow boron doped regions in a semiconductor device. In one embodiment of the invention an N-type semiconductor substrate (15) is provided having a first P-type region formed therein. A dielectric layer (16) is formed on the substrate surface and a material layer (17) doped with fluorinated boron is formed on the dielectric layer (16). A second P-type region (22), characterized by a high dopant concentration at the substrate surface and a uniform junction profile, is formed in the substrate adjacent to the first P-type region by diffusing boron atoms from the material layer (17) through the dielectric layer (16) and into the substrate (15). The second P-type region (22) has a very shallow junction depth which is closer to the substrate surface than the first P-type region.