Abstract: A method for forming an aluminum contact through an insulating layer includes the formation of an opening. A barrier layer is formed, if necessary, over the insulating layer and in the opening. A thin refractory metal layer is then formed over the barrier layer, and aluminum deposited over the refractory metal layer. Proper selection of the refractory metal layer and aluminum deposition conditions allows the aluminum to flow into the contact and completely fill it. Preferably, the aluminum is deposited over the refractory metal layer without breaking vacuum.

Abstract: A method is provided for forming a contact opening or via of a semiconductor integrated circuit, and an integrated circuit formed according to the same. A first metal region is formed over an underlying region. A first insulating layer is formed over the integrated circuit. A second insulating layer is then formed over the first insulating layer. A portion of the second insulating layer is etched to expose a portion of the first insulating layer wherein the exposed first insulating layer and the remaining second insulating layer form a substantially planar surface. A metal oxide layer is formed over the exposed first insulating layer and the remaining second insulating layer. A photoresist layer is formed and patterned over the metal oxide layer. The metal oxide layer is then selectively etched to form a via exposing a portion of the first insulating layer. The first insulating layer in the via is then selectively etched to expose a portion of the first metal region.

Abstract: An integrated circuit structure contains both highly resistive regions and highly conductive interconnect regions in a single layer of polycrystalline silicon. The resistive regions have a smaller cross section than the interconnect regions as a result of partial oxidation. Their thickness and width are reduced from that of the interconnect regions. The partial oxidation leaves an oxide region, derived from polycrystalline silicon, on both the top and sides of the resistive regions.

Abstract: A method for forming integrated circuit structures includes the formation of high-value resistive elements and low resistance interconnect in a single polycrystalline layer. In one embodiment, interconnect regions of the polycrystalline silicon layer are masked, and resistive element regions are partially oxidized to reduce the thickness of the polycrystalline layer in such regions. Resistivity of the interconnect regions may then be reduced by implanting a high level of impurities in them, or by forming a refractory metal silicide layer over the interconnect regions. The oxide formed over the resistive elements during the oxidation thereof protects them from either of the following process steps, so that no masking is required. In an alternative embodiment, silicidation of the interconnect regions of the polycrystalline silicon layer may be performed without the prior local oxidations of the resistive element regions.

Abstract: A method for forming field effect devices having lightly doped drain regions requires only a single dope and implant step. After patterning of the polycrystalline silicon gates, sloped sidewall spacers are formed alongside the gates. These spacers have a relatively linear slope from the top corners of the polycrystalline silicon gates to the substrate. A single implant of dopant results in heavily doped regions beyond the sidewall spacers with more lightly, and shallowly, doped regions next to the channel.

Abstract: A method for forming isolation structures in an integrated circuit, and the structures so formed, are disclosed. After definition of active regions of the surface is accomplished by provision of masking layers, recesses are etched into the exposed locations, to a depth on the order of the final thickness of the insulating isolation structure. Sidewall spacers of silicon dioxide, or another insulating amorphous material, are disposed along the sidewalls of the recesses, with silicon at the bottom of the recesses exposed. Selective epitaxial growth of silicon then forms a layer of silicon within the recesses, preferably to a thickness on the order of half of the depth of the recess. The epitaxial silicon is thermally oxidized, filling the recesses with thermal silicon dioxide, having a top surface which is substantially coplanar with the active regions of the surface.

Abstract: A method for fabrication of local interconnects in an integrated circuit, and an integrated circuit formed according to the same, is disclosed. According to the disclosed embodiment, a first and a second conductive structure are formed over the integrated circuit. An insulating layer is formed over the integrated. A first photoresist layer is formed over the insulating layer, patterned and developed. The insulating layer is etched to expose selected regions of the first and second conductive structures. A refractory metal layer is formed over the integrated circuit. A barrier layer is formed over the refractory metal layer, and optionally a refractory metal silicide layer is formed over the barrier layer. A second photoresist layer is formed over the barrier layer, patterned and developed.

Abstract: A method for forming a connection between two levels in a semiconductor structure includes first forming a VIA (14) through an insulating layer (12) to an underlying structure (10). Sidewall spacers (22) and (24) are formed on the vertical walls of the VIA (14). The spacers (22) and (24) have tapered surfaces. A barrier layer (30) is then formed over the bottom surface of the VIA followed by CVD deposition of a conductive layer (32) of WSi.sub.2 to provide a conformal conductive layer. An aluminum layer (38) is then deposited by physical vapor deposition techniques with the descending portions of layer (32) providing a conductive connection between the aluminum layer (38) and the lower structure (10) in the VIA (14).

Abstract: A method for forming aluminum metallization for contacting a conductive element in an integrated circuit, and an integrated circuit formed according to the same, is disclosed. According to a first disclosed embodiment, a first aluminum alloy layer is formed within the contact, optionally with a barrier layer between it and the underlying electrode. An etch stop layer is formed thereover, of a material which has a low etch rate to an aluminum etchant species. A second, thicker, aluminum alloy layer is formed thereover. The second aluminum layer is etched until the etch stop layer is reached; the mask for defining the metal line may have an edge within the dimensions of the contact opening. After removal of the exposed etch stop layer, a timed etch removes the first aluminum alloy layer, without exposing the bottom of the contact. The metal line may thus be safely formed, without requiring an enclosure around the contact opening.

Abstract: Local interconnect is defined in a polycrystalline silicon layer. Openings to underlying conducting regions are made through an insulating layer after the local interconnect conductor definition. A thin extra polycrystalline silicon layer is then deposited over the device and etched back to form polycrystalline silicon sidewall elements. These sidewalls connect the polycrystalline silicon local interconnect conductors to the underlying conductive regions. Standard silicidation techniques are then used to form a refractory metal silicide on the exposed underlying conductive regions, the polycrystalline silicon sidewall elements, and the polycrystalline silicon local interconnect conductors. This results in a complete silicided connection between features connected by the local interconnect conductors.

Abstract: A method for fabrication of local interconnects in an integrated circuit, and an integrated circuit formed according to the same, is disclosed. According to the disclosed embodiment, a first and a second conductive structure are formed over the integrated circuit. An insulating layer is formed over the integrated. A first photoresist layer is formed over the insulating layer, patterned and developed. The insulating layer is etched to expose selected regions of the first and second conductive structures. A refractory metal layer is formed over the integrated circuit. A barrier layer is formed over the refractory metal layer, and optionally a refractory metal silicide layer is formed over the barrier layer. A second photoresist layer is formed over the barrier layer, patterned and developed.

Abstract: A method for forming field oxide regions which results in reduced diffusion of the channel stop implant into the active regions of the substrate. According to the present invention, an opening is formed through an oxidation barrier to define the field oxide regions. A dielectric layer is then deposited over the device, followed by implantation of a channel stop region. With the dielectric layer in place, the field oxide region is formed. During formation of the field oxide, the channel stop region will not diffuse into the active regions in the substrate. The thickness and conformality of the dielectric layer will affect the distance that the channel stop implant resides from the edges of the field oxide region.

Abstract: A method for forming aluminum metallization for contacting a conductive element in an integrated circuit, and an integrated circuit formed according to the same, is disclosed. According to a first disclosed embodiment, a first aluminum alloy layer is formed within the contact, optionally with a barrier layer between it and the underlying electrode. An etch stop layer is formed thereover, of a material which has a low etch rate to an aluminum etchant species. A second, thicker, aluminum alloy layer is formed thereover. The second aluminum layer is etched until the etch stop layer is reached; the mask for defining the metal line may have an edge within the dimensions of the contact opening. After removal of the exposed etch stop layer, a timed etch removes the first aluminum alloy layer, without exposing the bottom of the contact. The metal line may thus be safely formed, without requiring an enclosure around the contact opening.

Abstract: A method for forming integrated circuit structures includes the formation of high-value resistive elements and low resistance interconnect in a single polycrystalline layer. In one embodiment, interconnect regions of the polycrystalline silicon layer are masked, and resistive element regions are partially oxidized to reduce the thickness of the polycrystalline layer in such regions. Resistivity of the interconnect regions may then be reduced by implanting a high level of impurities in them, or by forming a refractory metal silicide layer over the interconnect regions. The oxide formed over the resistive elements during the oxidation thereof protects them from either of the following process steps, so that no masking is required. In an alternative embodiment, silicidation of the interconnect regions of the polycrystalline silicon layer may be performed without the prior local oxidations of the resistive element regions.

Abstract: Field oxide regions are formed between drive regions of a silicon substrate by forming over the substrate a sandwich of silicon dioxide, silicon nitride and silicon dioxide layers, opening the layers to expose a portion of the silicon substrate, removing a layer of the exposed substrate, forming side wall spacers on the edges of the opening, removing a layer of the silicon substrate exposed between the side wall spacers, and then reaching the exposed substrate for the thermal oxidation of the exposed substrate for forming the field oxide region. In those structures in which the field oxide is buried in the substrate as shown in FIG. 12, it may be feasible to use thicker field oxide regions and thereby to reduce the need for the heavily doped surface layer under the field oxide.

Abstract: A method is provided for forming contact vias in an integrated circuit. Initially, a first buffer layer is formed over an insulating layer in an integrated circuit. The first buffer layer has a different etch rate from the insulating layer. A second buffer layer is then formed over the first buffer layer, with the second buffer layer having an etch rate which is faster than the first buffer layer. An isotropic etch is performed to create an opening through the second buffer layer and a portion of the first buffer layer. Because the second buffer layer etches faster than the first buffer layer, the slant of the sideswalls of the opening can be controlled. An anisotropic etch is then performed to complete formation of the contact via.

Abstract: A method for forming field effect devices having lightly doped drain regions requires only a single dope and implant step. After patterning of the polycrystalline silicon gates, sloped sidewall spacers are formed alongside the gates. These spacers have a relatively linear slope from the top corners of the polycrystalline silicon gates to the substrate. A single implant of dopant results in heavily doped regions beyond the sidewall spacers with more lightly, and shallowly, doped regions next to the channel.

Abstract: A method of forming an insulated-gate field-effect transistor, and the transistor formed thereby, is described. According to a first embodiment, an inverted-T gate structure is formed by the deposition of a polycrystalline silicon layer, followed by the deposition of a metal silicide layer thereover. The metal silicide layer is etched with etchant which does not significantly etch polysilicon, to define the upper portion of the gate electrode. The reachthrough lightly-doped source/drain extensions are then implanted through the polysilicon layer, using the upper gate electrode portion as a mask. Sidewall spacers are formed on the sides of the upper portion of the gate electrode, and the polysilicon etched using the spacers as a mask, to define the inverted-T gate structure.

Abstract: A method for fabricating integrated circuits is used to improve contacts between polycrystalline interconnect and underlying polycrystalline or monocrystalline silicon regions. After contact openings are formed, a layer of titanium is deposited over the integrated circuit. The titanium is reacted in nitrogen to form a silicide layer only in the openings. Titanium nitride and unreacted titanium are then removed, and a layer of polycrystalline silicon deposited and patterned. The silicide layer between the polycrystalline interconnect and the underlying silicon ensures that a high quality contact is formed.

Abstract: A silicide layer, to improve conductivity, is formed over a first layer of polycrystalline silicon, followed by a second layer of polycrystalline silicon. This structure is then patterned to form gate regions over active areas. A layer of metal silicide is formed over the entire surface of the chip, and patterned to form local interconnect. Etching of the second metal silicide layer is stopped by the second polycrystalline silicon layer, thereby protecting the rust metal silicide layer from damage.