Abstract: A composite gate electrode layer incorporates a diffusion-retarding barrier layer disposed at the bottom of the gate electrode layer to reduce the amount of dopant which diffuses into the gate dielectric layer from the gate electrode layer. A lower nitrogen-containing gate electrode layer provides a diffusion-retarding barrier layer against dopant diffusion into the gate dielectric layer disposed therebelow, and an upper gate electrode layer is formed upon the lower layer and is doped to form a highly conductive layer. Together the first and second gate electrode layers form a composite gate electrode layer which incorporates a diffusion-retarding barrier layer adjacent to the underlying gate dielectric layer. The barrier layer may be formed by annealing a first polysilicon layer in a nitrogen-containing ambient, such as N.sub.2, NO, N.sub.2 O, and NH.sub.

Abstract: A method of making an IGFET with a selectively doped multilevel polysilicon gate that includes upper and lower polysilicon gate levels is disclosed.

Abstract: An IGFET with metal spacers is disclosed. The IGFET includes a gate electrode on a gate insulator on a semiconductor substrate. Sidewall insulators are adjacent to opposing vertical edges of the gate electrode, and metal spacers are formed on the substrate and adjacent to the sidewall insulators. The metal spacers are electrically isolated from the gate electrode but contact portions of the drain and the source. Preferably, the metal spacers are adjacent to edges of the gate insulator beneath the sidewall insulators. The metal spacers are formed by depositing a metal layer over the substrate then applying an anisotropic etch. In one embodiment, the metal spacers contact lightly and heavily doped drain and source regions, thereby increasing the conductivity between the heavily doped drain and source regions and the channel underlying the gate electrode. The metal spacers can also provide low resistance drain and source contacts.

Abstract: An IGFET with a gate electrode and a source contact in a trench is disclosed. The IGFET includes a trench with opposing sidewalls and a bottom surface in a semiconductor substrate, a gate insulator on the bottom surface, a gate electrode on the gate insulator, a source contact on the bottom surface, insulative spacers between the gate electrode, the source contact and the sidewalls, and a source and drain adjacent to the bottom surface.

Abstract: An IGFET with a silicide contact on an ultra-thin gate is disclosed. A method of forming the IGFET includes forming a gate over a semiconductor substrate, forming a source and a drain in the substrate, depositing a contact material over the gate, and reacting the contact material with the gate to form a silicide contact on the gate and consume at least one-half of the gate. By consuming such a large amount of the gate, a relatively thin gate can be converted into an ultra-thin gate with a thickness on the order of 100 to 200 angstroms. Preferably, the bottom surface of the gate is essentially undoped before reacting the contact material with the gate, and reacting the contact material with the gate pushes a peak concentration of a dopant in the gate towards the substrate so that a heavy concentration of the dopant is pushed to the bottom surface of the gate without being pushed into the substrate.

Abstract: In the fabrication of an integrated circuit having both N MOSFETs and P MOSFETs in which the respective N-type species and P-type species have substantially different diffusivities, the source implant of the dopant species having a the higher diffusivity is advantageously delayed until a contact masking process step. By delaying the dopant species having the higher diffusivity, depletion of the dopant by subsequent annealing steps is avoided. P MOSFETs formed using a high diffusivity boron implant species in an integrated circuit including both P MOSFETs and N MOSFET are fabricated with no source implant in the source regions during formation of the gate electrodes and sidewall spaces.

Abstract: A photolithographic system includes individually controllable radiation sources for forming an image pattern on an image plane without using a reticle or mask during fabrication of an integrated circuit device. The radiation sources are selectively activated as they scan the image plane. The image pattern can consist of parallel lines having identical widths and varying lengths, or alternatively, pixels having identical shapes and sizes. The radiation sources can be arranged as a linear array, or a staggered array, to achieve the desired linear density. Suitable radiation sources include light pipes, light emitting diodes, and laser diodes. Preferably, each of the activated radiation sources provides an exposure field of less than 0.1 microns on the image plane, and at least two of the radiation sources must be activated to provide the minimum line width of the image pattern.

Abstract: Each circuit block of a plurality of circuit blocks on a semiconductor substrate is imaged in an exposure field defined by a reticle. The circuit blocks are separated and electrically isolated within the semiconductor substrate by an isolation such as a field oxide or trench isolation. The circuit blocks are globally interconnected by depositing a blanket metal layer, masking the metal layer and etching the metal layer using a stitching reticle having an exposure field overlapping the plurality of circuit blocks. The combination of reticle-imaged circuit blocks allows each individual circuit block to be fabricated independently, using independent imaging resolution, layout rules, design rules, different polysilicon sizes and source/drain region sizes and the like. In addition different reticles, including different reticle types, resolutions and qualities may be used to construct the various circuit blocks.

Abstract: A method of making NMOS and PMOS devices with different gate lengths includes providing a semiconductor substrate with first and second active regions, forming a first gate over a portion of the first active region and a second gate over a portion of the second active region, wherein the first and second gates are formed in sequence and have different lengths, and forming a source and drain in the first active region and a source and drain in the second active region. Preferably, the first gate is defined by a first photoresist layer patterned with a first exposure time, the second gate is defined by a second photoresist layer patterned with a second exposure time, and the difference in gate lengths is due primarily to a difference between the first and second exposure times.

Abstract: An IGFET with a gate electrode and metal spacers in a trench is disclosed. The IGFET includes a trench with opposing sidewalls and a bottom surface in a semiconductor substrate, metal spacers adjacent to the sidewalls and the bottom surface, a gate insulator on the bottom surface between the metal spacers, protective insulators on the metal spacers, a gate electrode on the gate insulator and protective insulators, and a source and drain adjacent to the bottom surface.

Abstract: A resistor protect mask is used on a shallow trench isolation device junction to cover a device area except for a strip on the perimeter of the device area. The silicide layer formed on the central surface portion of the device and the strip area on the perimeter of the device upon which silicide formation is prevented forms a test structure for evaluation of junction formation that is immune from the effects of silicide formation on a device trench sidewall. Electrical tests and leakage measurements upon the test structure are compared directly to similar silicide shallow trench isolated devices which do not incorporate the resistor protect mask and shallow trench isolated devices without silicide to determine whether salicide processing is a cause of junction effects including junction leakage and short-circuiting.

Abstract: A method of inspecting a lens includes projecting a first amount of radiation through a first test pattern and the lens to provide a first lens error associated with a first heating of the lens, projecting a second amount of radiation through a second test pattern and the lens to provide a second lens error associated with a second heating of the lens, and using the first and second lens errors to provide image displacement data that varies as a function of heating the lens. In this manner, corrections can be made for localized lens heating that is unique to a given reticle. The method is well-suited for photolithographic systems such as step and repeat systems.

Abstract: A broadband pyrometer is used for sensing temperature of a semiconductor wafer in an RTA system in association with a monochromator to cancel the backside characteristics of the semiconductor wafer. A rapid thermal anneal (RTA) system includes a rapid thermal anneal (RTA) chamber, a heating lamp arranged in the vicinity of the RTA chamber for heating interior to the RTA chamber, a broadband pyrometer disposed in the vicinity of the RTA chamber and directed to measure interior to the RTA chamber, and a grating monochromator connected to the broadband pyrometer.

Abstract: A method of forming a shallow junction in an IGFET is disclosed. The method includes forming a gate insulator on a semiconductor substrate of first conductivity type, forming a gate electrode on the gate insulator, forming a sidewall insulator on an edge of the gate electrode, forming a silicon-based spacer over the substrate such that the sidewall insulator separates and electrically isolates the spacer and the gate electrode, and diffusing a dopant of second conductivity type from the spacer into the substrate. The diffused dopant forms a shallow region of second conductivity type in the substrate, and a shallow junction is substantially laterally aligned with the edge of the gate electrode.

Abstract: An oxide layer is thermally grown over a semiconductor body, and openings are etched in the oxide layer to expose portions of the surface of the semiconductor body. Then, epitaxial regions are grown from the semiconductor body into the openings in the oxide layer, which epitaxial regions will eventually become the active regions of devices.

Abstract: After growth of a thin oxide on a silicon semiconductor body, and formation of a gate thereover, a blanket layer of oxide is deposited over the resulting structure, this oxide layer having, as measured from the surface of the silicon body, relatively thick regions adjacent the sides of the gate and relatively thin regions extending therefrom. Upon implant of ions, the relatively thick regions block ions from passing therethrough into the semiconductor body, while the relatively thin regions allow passage of ions therethrough into the body. After drivein of the ions, the thick layer of oxide is isotopically etched to take a substantially uniform layer therefrom over the entire surface of the thick oxide layer, so that the thick regions thereof are reduced in width. Upon a subsequent ion implant step, the thick regions, now reduced in width from the sides of the gate, block passage of ions therethrough, while the thin regions allow ions therethrough into the silicon body.

Abstract: A method of planarizing a semiconductor layer by use of a plasma etch step which also etches vias having a tapered profile is made possible by selecting a conformal layer preferably of a different material than the material through which the via is to be provided such that a plasma etch will establish differing etch rates in the conformal and underlying layers.

Abstract: A reverse mask is formed after the first ion implantation step by applying a second masking material to at least fill the opening in the first mask layer and removing the second mask material to reveal at least a portion of the first mask layer. The first mask layer is then selectively removed with any superimposed second mask layer material thereon. This forms a truly inverse mask. Second conductivity impurities are then introduced through the inverse mask to form self-aligned complementary wells in a substrate.