摘要:
A method for forming a gate dielectric having different thickness begins by providing a substrate (12). A sacrificial oxide (14) is formed overlying the substrate (12). A first portion (11) of the sacrificial oxide (14) is exposed to a carbon-containing plasma environment (20). This carbon-containing plasma environment (20) forms a carbon-containing layer (24) within the region (11). After forming this region (24), a wet etch chemistry (22) is used to remove remaining portions of the sacrificial oxide (14) without forming a layer (24) in the region (13). Furnace oxidation is then used to form regions (26a) and (26b) wherein the growth of region (26a) has been retarded by the presence of the region (24). Therefore, the regions (26a) and (26b) are differing in thickness and can be used to make different transistors having different current gains.
摘要:
A process for reducing halogen concentration in a material layer (56) includes the deposition of a dielectric layer (58) overlying the material layer (56). An annealing process is carried out to diffuse halogen atoms from the material layer (56) into the overlying dielectric layer (58). Once the diffusion process is complete, the dielectric layer (58) is removed.
摘要:
A high quality thin dielectric layer is achieved by annealing a substrate and base oxide layer at a first temperature in a first ambient and subsequently annealing the substrate and base oxide layer at a second temperature in a second ambient, the base oxide layer overlying a top surface of the substrate. Prior to the first anneal, the base oxide layer has an initial thickness and density. The first anneal causes a first density and thickness change in the base oxide layer from the initial thickness and density to a first thickness and density, with no incorporation of a component of the ambient within the base oxide layer. The first thickness is less than the initial thickness and the first density is greater than the initial density. The second anneal causes a second density and thickness change in the base oxide layer from the first thickness and density to a second thickness and density. The second thickness is larger than the first thickness and the second density is on the order of the greater than or equal to the first density.
摘要:
A method for forming an oxynitride gate dielectric layer (202, 204) begins by providing a semiconductor substrate (200). This semiconductor substrate is cleaned via process steps (10-28). Optional nitridation and oxidation are performed via steps (50 and 60) to form a thin interface layer (202). Bulk oxynitride gate deposition occurs via a step (70) to form a bulk gate dielectric material (204) having custom tailored oxygen and nitrogen profile and concentration. A step (10) is then utilized to in situ cap this bulk dielectric layer (204) with a polysilicon or amorphous silicon layer (208). The layer (208) ensures that the custom tailors oxygen and nitrogen profile and concentration of the underlying gate dielectric (204) is preserved even in the presence of subsequent wafer exposure to oxygen ambients.
摘要:
A process for the fabrication of an MOSFET device includes the formation of a buffer layer (28) overlying the surface of a semiconductor substrate (14) adjacent to a gate electrode (18). A defect compensating species is diffused through the buffer layer (28) and through a gate dielectric layer (12) to form a defect-compensating region (30) at the surface (14) of the semiconductor substrate (10). The defect-compensating region (30) in conjunction with the buffer layer (28) minimize and control the population of point defects in the channel region (22) of the semiconductor substrate (10). By controlling the population of point defects in the channel region (22), a substantially uniform doping profile is maintained in a shallow doped region (16) formed in the semiconductor substrate (10) at the substrate surface (14). The maintenance of a uniform doping profile in the shallow doped region (16) results in improved threshold voltage stability as the lateral dimension of the channel region (22) is reduced.
摘要:
A method of making a high quality thin dielectric layer includes annealing a substrate and a base oxide layer overlying a top surface of the substrate at a first temperature in a first ambient and annealing the substrate and base oxide layer at a second temperature in a second ambient subsequent to the first anneal. The first ambient includes an inert gas ambient selected from the group consisting of a nitrogen, argon, and helium ambient. Prior to the first anneal, the base oxide layer has an initial thickness and an initial density. The first anneal causes a first density and thickness change in the base oxide layer from the initial thickness and density to a first thickness and density, with no incorporation of nitrogen, argon, or helium of the ambient within the base oxide layer. The first thickness is less than the initial thickness and the first density is greater than the initial density. The second anneal causes a second density and thickness change in the base oxide layer from the first thickness and density to a second thickness and density. The second thickness is larger than the first thickness and the second density is on the order of the greater than or equal to the first density.
摘要:
A method for forming an oxynitride gate dielectric layer (202, 204) begins by providing a semiconductor substrate (200). This semiconductor substrate is cleaned via process steps (10-28). Optional nitridation and oxidation are performed via steps (50 and 60) to form a thin interface layer (202). Bulk oxynitride gate deposition occurs via a step (70) to form a bulk gate dielectric material (204) having custom tailored oxygen and nitrogen profile and concentration. A step (10) is then utilized to in situ cap this bulk dielectric layer (204) with a polysilicon or amorphous silicon layer (208). The layer (208) ensures that the custom tailors oxygen and nitrogen profile and concentration of the underlying gate dielectric (204) is preserved even in the presence of subsequent wafer exposure to oxygen ambients.
摘要:
An annealed amorphous silicon layer is formed prior to forming field isolation regions when using in a LOCOS field isolation process. The annealed amorphous silicon layer helps to reduce encroachment compared to conventional LOCOS field isolation process and helps to reduce the likelihood of forming pits within a substrate compared to a PBL field isolation process. The annealed amorphous silicon layer may be used in forming field isolation regions that defines the active regions between transistors including MOSFETs and bipolar transistors. Doped silicon or a silicon-rich silicon nitride layer may be used in place of conventional materials. The anneal of the amorphous silicon layer may be performed after forming a silicon nitride layer if the silicon nitride layer is deposited at a temperature no higher than 600 degrees Celsius.
摘要:
The reliability of integrated circuits fabricated with trench isolation is improved by increasing the thickness of the gate dielectric overlying the trench corner. After the trench isolation region (40, 56) has been formed a thin layer of silicon dioxide (44) is chemically vapor deposited over the trench isolation region (44) and the adjacent active region (23). A transistor gate electrode (46) is subsequently formed over the thin layer of silicon dioxide (44). The thin layer of silicon dioxide (44) increases the thickness of the gate dielectric that lies between the transistor gate electrode (46) and the trench corner, and therefore the breakdown voltage of the gate dielectric at the trench corner is increased.
摘要:
A semiconductor device (10) having two different gate dielectric thicknesses is formed using a single high-k dielectric layer, preferably a metal oxide. A thicker first gate dielectric (16) is formed in a region of the device for higher voltage requirements, e.g. an I/O region (24). A thinner second gate dielectric (20) is formed in a region of the device for lower voltage requirements, e.g. a core device region (22). First and second dielectrics are preferably silicon dioxide or oxynitride. A metal oxide (26) is deposited over both dielectrics, followed by deposition of a gate electrode material (28). By using a single metal oxide layer in forming the gate dielectric stack for each transistor, together with high quality silicon dioxide or oxynitride dielectric layers, problems associated with selective etching of the metal oxide may be avoided, as may problems associated with various interfaces between the metal oxide and damaged or treated surfaces.