Abstract: A method for slowing the diffusion of boron ions in a CMOS structure includes a preanneal step which can be incorporated as part of a step in which silane is deposited across the surface of the wafer. After the last implant on a CMOS device, silane (SiH.sub.4) is deposited over the surface of the wafer using a chemical vapor deposition (CVD) tool. The deposition of silane is done at 400.degree. C. The temperature is raised in the CVD tool to a temperature in the range of 550.degree. C. to 650.degree. C. and held for 30-60 minutes. This temperature does not affect the thin film of silicon which is formed from the silane, yet provides the necessary thermal cycle to "repair" the crucial first 200 .ANG. to 600 .ANG. of the silicon surface. Normal processing steps, including a rapid thermal anneal for 30 seconds at 1025.degree. C. follow. The RTA is necessary to activate the dopants (arsenic and boron) in the source and drain of the respective devices.

Abstract: One method of forming a semiconductor device includes forming a gate electrode on a substrate and then forming a spacer adjacent to a sidewall of the gate electrode. An active region is formed in the substrate adjacent to the spacer and spaced apart from the gate electrode using a first dopant material of a first conductivity type. A protecting layer is formed over the active region and adjacent to the spacer. At least a portion of the spacer is then removed to form an opening between the protecting layer and the gate electrode. In some instances, the spacer may be formed by independent deposition of two different materials (e.g., silicon nitride and silicon dioxide), one of which can be selectively removed with respect to the other. A lightly-doped region is formed in the substrate adjacent to the gate electrode using a second dopant material of the first conductivity type.

Abstract: A semiconductor device having an elevated gate electrode and elevated active regions and a process for manufacturing such a device is disclosed. In accordance with one embodiment a semiconductor device is formed by forming a gate insulating layer over a substrate and forming a photoresist block over the gate insulating layer. First portions of the gate insulating layer and first portions of the substrate adjacent the photoresist block are then removed to form a first elevated substrate region under the gate insulating layer and photoresist block. Edge portions of the photoresist block are then removed. Second portions of the gate insulating layer and portions of the first elevated substrate region adjacent the photoresist block are then removed to form second elevated substrate regions adjacent the photoresist block, and a dopant is implanted into the second elevated substrate regions to form source/drain regions, and the photoresist block is used to form a gate electrode.

Abstract: A semiconductor device having a gate electrode with a sidewall air gap is provided. In accordance with this embodiment, at least one gate electrode is formed over a substrate. A spacer is then formed adjacent an upper sidewall portion of the gate electrode such that an open area is left beneath the spacer. Next, a dielectric layer is formed over the spacer and the gate electrode, thereby leaving an air gap in the open area. In accordance with one aspect of the invention, both the gate electrode and the spacer adjacent the gate electrode are formed from polysilicon. This, for example, allows the formation of a wider contact area to the gate electrode.

Abstract: A CMOS semiconductor device having NMOS source/drain regions formed using multiple spacers has at least one NMOS region and at least one PMOS region. A first n-type dopant is selectively implanted into an NMOS active region of the substrate adjacent a NMOS gate electrode to form a first n-doped region in the NMOS active region. A first NMOS spacer is formed on a sidewall of the NMOS gate electrode and a first PMOS spacer on a sidewall of a PMOS gate electrode. A second n-type dopant is selectively implanted into the NMOS active region using the first NMOS spacer as a mask. A p-type dopant is selectively implanted into a PMOS active region using the first PMOS spacer as a mask to form a first p-doped region in the PMOS active region. A second NMOS spacer and a second PMOS spacer are formed adjacent the first NMOS spacer and first PMOS spacer, respectively.

Abstract: An improved oscillator test structure is disclosed. A structure according to one embodiment includes an odd plurality of first transistor pairs formed on a predetermined area of a semiconductor substrate. The transistor pairs are electrically connected in a serial ring. The structure also includes at least one second transistor pair, also formed within the predetermined area on the substrate, but electrically isolated from the odd plurality of first transistor pairs.

Abstract: A semiconductor device having asymmetrically-doped gate electrode and active region and a process of fabricating such a device is provided. According to one embodiment of the invention, a polysilicon layer is formed over the substrate. The polysilicon layer is then implanted with a first dopant to form a doped polysilicon layer. Portions of the doped polysilicon layer are then removed to form at least one gate electrode. Active regions of the substrate adjacent the gate electrode are implanted with a second dopant to form source/drain regions in the substrate. In this manner, the implant used to form the source/drain regions may be decoupled from the implant used to form the gate electrode. This, for example, allows for shallower source/drain regions to be formed without the formation of the depletion layer in the gate electrode.

Abstract: The formation of a shortage protection region is disclosed. In one embodiment, a method includes three steps. In the first step, a first ion implantation is applied to form lightly doped regions within a semiconductor substrate adjacent to sidewalls of a gate over the substrate. In the second step, two spaces are formed on the substrate, each adjacent to a sidewall of the gate, so that a second ion implantation forms heavily doped regions within the substrate adjacent to the first spacers. In the third step, two additional spacers are formed on the substrate, each overlapping and extending beyond a corresponding spacer previously formed. Thus, a third ion implantation forms lightly doped shortage protection regions within the substrate adjacent to the spacers most recently formed.

Abstract: A method and structure for optimizing the performance of a semiconductor device having dense transistors. A method consistent with the present invention includes forming a first test structure on a first substrate portion. The first test structure includes a transistor having a gate electrode formed at a design width and at a first line spacing similar to the line spacing of a dense transistor. One or more electrical properties the transistor of the first test structure is measured. A second test structure is formed on a second substrate portion. The second test structure includes a transistor having a gate electrode formed at the same design width as the transistor of the first test structure and at a second line spacing greater than the first line spacing. One or more electrical properties of the transistor of the second test structure are measured.

Abstract: Semiconductor devices having one or more asymmetric background dopant regions and methods of fabrication thereof are provided. The asymmetric background dopant regions may be formed using a patterned mask with wider openings than conventional masks while substantially maintaining device performance. This can, for example, facilitate the fabrication process and allow greater flexibility in the choice of photolithography tools.

Abstract: A method of forming a conductive plug in an interlevel dielectric includes forming a lower dielectric layer over a semiconductor substrate. A first etch mask is formed over the lower dielectric layer and is patterned using a reticle. A first etch is applied through an opening in the first etch mask to form an opening in the lower dielectric layer. A lower conductor is formed in the opening in the lower dielectric layer. A conducting layer is formed over the lower dielectric layer and the lower conductor. A second etch mask is formed over the conducting layer and is patterned using the reticle. A second etch is applied through an opening in the second etch mask to form a contact pad from an unetched portion of the conducting layer. An upper dielectric layer is formed over the lower dielectric layer and the contact pad. A third etch mask is formed over the upper dielectric layer and is patterned using the reticle.

Abstract: In semiconductor device fabrication process, an active region of a semiconductor device is formed by diffusing a dopant out of a sidewall spacer. In the fabrication process, a gate electrode having a sidewall adjacent an active region is formed on a substrate and a doped spacer layer having a dopant disposed therein is formed over the substrate and gate electrode. A portion of the spacer layer is then removed to form a spacer on the sidewall of the gate electrode. The dopant in the spacer is diffused into the substrate to form a lightly-doped region in the active region of the substrate. The lightly-doped region may form an LDD region of an LDD structure.