Abstract: A method of fabricating a vertical channel transistor, comprising the following steps. A semiconductor substrate having an upper surface is provided. A high doped N-type lower epitaxial silicon layer is formed on the semiconductor substrate. A low doped P-type middle epitaxial silicon layer is formed on the lower epitaxial silicon layer. A high doped N-type upper epitaxial silicon layer is formed on the middle epitaxial silicon layer. The lower, middle, and upper epitaxial silicon layers are etched to form a epitaxial layer stack defined by isolation trenches. Oxide is formed within the isolation trenches. The oxide is etched to form a gate trench within one of the isolation trenches exposing a sidewall of the epitaxial layer stack facing the gate trench. Multi-quantum wells or a stained-layer super lattice is formed on the exposed epitaxial layer stack sidewall. A gate dielectric layer is formed on the multi-quantum wells or the stained-layer super lattice and within the gate trench.

Abstract: A method for a vertical transistor by selective epi deposition to form the conductive source, drain, and channel layers. The conductive source, drain, and channel layers are preferably formed by a selective epi process. Dielectric masks define the conductive layers and make areas to form vertical contacts to the conductive S/D and channel layers.

Abstract: A method for a vertical MOS transistor whose vertical channel width can be accurately defined and controlled. Isolation regions are formed in a substrate. The isolation regions defining an active area. Then, we form a source region in the active area. A dielectric layer is formed over the active area and the isolation regions. We form a barrier layer over the dielectric layer. We form an opening in the barrier layer. A gate layer is formed in the opening. We form an insulating layer over the conductive layer and the barrier layer. We form a gate opening through the insulating layer, the gate layer and the dielectric layer to expose the source region. Gate dielectric spacers are formed over the sidewalls of the gate layer. Then, we form a conductive plug filling the gate opening. The insulating layer is removed. We form a drain region in top and side portions of the conductive plug and form doped gate regions in the gate layer. The remaining portions of the conductive plug comprise a channel region.

Abstract: A method for forming a gate dielectric having regions with different dielectric constants. A low-K dielectric layer is formed over a semiconductor structure. A dummy dielectric layer is formed over the low-K dielectric layer. The dummy dielectric layer and low-K dielectric layer are patterned to form an opening. The dummy dielectric layer is isontropically etched selectively to the low-K dielectric layer to form a stepped gate opening. A high-K dielectric layer is formed over the dummy dielectric and in the stepped gate opening. A gate electrode is formed on the high-K dielectric layer.

Abstract: A method for forming shallow trench isolation wherein oxide divots at the edge of the isolation and active regions are reduced or eliminated is described. A trench is etched into a semiconductor substrate. An oxide layer is deposited overlying the semiconductor substrate and filling the trench. Nitrogen atoms are implanted into the oxide layer overlying the trench. The substrate is annealed whereby a layer of nitrogen-rich oxide is formed at the surface of the oxide layer overlying the trench.

Abstract: A method for forming a thicker silicide over a MOS device is described. This is achieved using a process where the gate structure is formed by conventional techniques upon a substrate. A low-energy implantation is performed to form lightly doped source and drain (LDD) regions in the substrate in the areas not protected by the gate structure. A first spacer composed of tetraethyl-oxysilane (TEOS oxide), for example, is formed along the sidewalls of the gate structure. A second low-energy implantation is performed to form the source and drain (S/D) in the areas not protected by the gate structure and first spacer. A layer of metal such as titanium (Ti), for example, is then deposited over the surface of the gate structure. A second sidewall spacer composed of titanium nitride (TiN), for example, is formed along the sidewalls of the gate structure covering the metal over the first sidewall spacer. A layer of polysilicon is then deposited over the surface of the gate structure.

Abstract: A method for forming a gate dielectric having regions with different dielectric constants. A low-K dielectric layer is formed over a semiconductor structure. A dummy dielectric layer is formed over the low-K dielectric layer. The dummy dielectric layer and low-K dielectric layer are patterned to form an opening. The dummy dielectric layer is isontropically etched selectively to the low-K dielectric layer to form a stepped gate opening. A high-K dielectric layer is formed over the dummy dielectric and in the stepped gate opening. A gate electrode is formed on the high-K dielectric layer.

Abstract: A method for a self aligned TX with elevated source/drain (S/D) regions on an insulated layer (oxide) by forming a trench along side the STI and filling the trench with oxide. STI regions are formed in a substrate. A gate structure is formed. LDD regions are formed adjacent to the gate structure in the substrate. Spacers are formed on the sidewall of the gate structure. We etch S/D trenches between the STI regions and the first spacers. The S/D trenches are filled with a S/D insulating layer. Elevated S/D regions are formed over the S/D insulating layer and the LDD regions. A top isolation layer is formed over the STI regions. The invention builds the raised source/drain (S/D) regions on an insulating layer and reduces junction leakage and hot carrier degradation to gate oxide.

Abstract: A method for a vertical transistor by selective epi deposition to form the conductive source, drain, and channel layers. The conductive source, drain, and channel layers are preferably formed by a selective epi process. Dielectric masks define the conductive layers and make areas to form vertical contacts to the conductive S/D and channel layers.

Abstract: A method of fabricating a vertical channel transistor, comprising the following steps. A semiconductor substrate having an upper surface is provided. A high doped N-type lower epitaxial silicon layer is formed on the semiconductor substrate. A low doped P-type middle epitaxial silicon layer is formed on the lower epitaxial silicon layer. A high doped N-type upper epitaxial silicon layer is formed on the middle epitaxial silicon layer. The lower, middle, and upper epitaxial silicon layers are etched to form a epitaxial layer stack defined by isolation trenches. Oxide is formed within the isolation trenches. The oxide is etched to form a gate trench within one of the isolation trenches exposing a sidewall of the epitaxial layer stack facing the gate trench. Multi-quantum wells or a stained-layer super lattice is formed on the exposed epitaxial layer stack sidewall. A gate dielectric layer is formed on the multi-quantum wells or the stained-layer super lattice and within the gate trench.

Abstract: A method for forming shallow trench isolation wherein oxide divots at the edge of the isolation and active regions are reduced or eliminated is described. A trench is etched into a semiconductor substrate. An oxide layer is deposited overlying the semiconductor substrate and filling the trench. Nitrogen atoms are implanted into the oxide layer overlying the trench. The substrate is annealed whereby a layer of nitrogen-rich oxide is formed at the surface of the oxide layer overlying the trench.

Abstract: A new method of forming shallow trench isolations has been described. A silicon semiconductor substrate is provided. A silicon nitride layer is deposited overlying the substrate. A polysilicon layer is deposited overlying the silicon nitride layer. An oxidation mask is deposited overlying the polysilicon layer. The oxidation mask, polysilicon layer, silicon nitride layer, and the silicon semiconductor substrate are patterned to form trenches for planned shallow trench isolations. The silicon semiconductor substrate exposed within the trenches is oxidized to form an oxide liner layer within the trenches wherein the oxidation mask prevents oxidation of the polysilicon layer. Thereafter the oxidation mask is removed. A trench oxide layer is deposited overlying the liner oxide layer and filling the trenches.

Abstract: A method of forming a a self-aligned elevated transistor using selective epitaxial growth is described. An oxide layer is provided overlying a semiconductor substrate. The oxide layer is etched through to the semiconductor substrate to form a trench having a lower portion contacting the substrate and an upper portion having a width larger than the width of the lower portion. A silicon layer is grown within the trench using selective epitaxial growth wherein the silicon layer fills the lower portion and partially fills the upper portion. Nitride spacers are formed on the sidewalls of the trench. A polysilicon layer is deposited overlying the oxide layer and within the trench and etched back to form a gate electrode within the trench between the nitride spacers. The nitride spacers are etched away where they are not covered by the gate electrode leaving thin nitride spacers on sidewalls of the gate electrode.

Abstract: A method for forming a transistor having low overlap capacitance by forming a microtrench at the gate edge to reduce effective dielectric constant is described. A gate electrode is provided overlying a gate dielectric layer on a substrate and having a hard mask layer thereover. An oxide layer is formed overlying the substrate. First spacers are formed on sidewalls of the gate electrode and overlying the oxide layer. Source/drain extensions are implanted. Second spacers are formed on the first spacers. Source/drain regions are implanted. A dielectric layer is deposited overlying the gate electrode and the oxide layer and planarized to the hard mask layer whereby the first and second spacers are exposed. The exposed second spacers and underlying oxide layer are removed. The exposed substrate underlying the second spacers is etched into to form a microtrench undercutting the gate oxide layer at an edge of the gate electrode.

Abstract: A method for a self aligned TX with elevated source/drain (S/D) regions on an insulated layer (oxide) by forming a trench along side the STI and filling the trench with oxide. STI regions are formed in a substrate. A gate structure is formed. LDD regions are formed adjacent to the gate structure in the substrate. Spacers are formed on the sidewall of the gate structure. We etch S/D trenches between the STI regions and the first spacers. The S/D trenches are filled with a S/D insulating layer. Elevated S/D regions are formed over the S/D insulating layer and the LDD regions. A top isolation layer is formed over the STI regions. The invention builds the raised source/drain (S/D) regions on an insulating layer and reduces junction leakage and hot carrier degradation to gate oxide.

Abstract: A method for forming a gate dielectric having regions with different dielectric constants. A dummy dielectric layer is formed over a semiconductor structure. The dummy dielectric layer is patterned to form a gate opening. A high-K dielectric layer is formed over the dummy dielectric and in the gate opening. A low-K dielectric layer is formed on the high-K dielectric layer. Spacers are formed on the low-K dielectric layer at the edges of the gate opening. The low-K dielectric layer is removed from the bottom of the gate opening between the spacers. The spacers are removed to form a stepped gate opening. The stepped gate opening has both a high-K dielectric layer and a low-K dielectric layer on the sidewalls and at the edges of the bottom of the gate opening and only a high-k dielectric layer in the center of the bottom of the stepped gate opening. A gate electrode is formed in the stepped gate opening.

Abstract: A method of forming shallow trench isolations is described. A plurality of isolation trenches are etched through a first etch stop layer into the underlying semiconductor substrate. An oxide layer is deposited over the first etch stop layer and within the isolation trenches using a high density plasma chemical vapor deposition process (HDP-CVD) wherein after the oxide layer fills the isolation trenches, the deposition component is discontinued while continuing the sputtering component until corners of the first etch stop layer are exposed at edges of the isolation trenches whereby the oxide layer within the isolation trenches is disconnected from the oxide layer overlying the first etch stop layer. Thereafter, a second etch stop layer is deposited overlying the oxide layer within the isolation trenches, the oxide layer overlying the first etch stop layer, and the exposed first etch stop layer corners.

Abstract: A method of forming a pseudo-SOI device having elevated source/drain (S/D) regions that can be extended for use as local interconnect is described. Shallow trench isolation (STI) regions separating adjacent active regions are provided within a semiconductor substrate. Polysilicon gate electrodes and associated SID extensions are fabricated in and on the substrate in the active regions wherein a hard mask layer overlies each of the gate electrodes. Dielectric spacers are formed on sidewalls of each of the gate electrodes. A polysilicon layer is deposited overlying the gate electrodes and the substrate. The polysilicon layer is polished back with a polish stop at the hard mask layer. The polysilicon layer is etched back whereby the polysilicon layer is recessed with respect to the gate electrodes. Thereafter, the polysilicon layer is etched away overlying the STI regions where a separation between adjacent active areas is desired.

Abstract: A method and apparatus for performing nickel salicidation is disclosed. The nickel salicide process typically includes: forming a processed substrate including partially fabricated integrated circuit components and a silicon substrate; incorporating nitrogen into the processed substrate; depositing nickel onto the processed substrate; annealing the processed substrate so as to form nickel mono-silicide; removing the unreacted nickel; and performing a series procedures to complete integrated circuit fabrication. This nickel salicide process increases the annealing temperature range for which a continuous, thin nickel mono-silicide layer can be formed on silicon by salicidation. It also delays the onset of agglomeration of nickel mono-silicide thin-films to a higher annealing temperature. Moreover, this nickel salicide process delays the transformation from nickel mono-silicide to higher resistivity nickel di-silicide, to higher annealing temperature.

Abstract: A method is provided to reduce poly depletion in MOS transistors. Conventionally, after a polysilicon electrode has been doped, an anneal step is usually performed to activate the dopants. However, the anneal step may be insufficient to drive the implanted impurities down the entire depth of the polysilicon electrode. Consequently, a portion of the polysilicon gate nearest to the gate oxide will be depleted of dopants. This poly depletion will have a detrimental effect on the control of the threshold voltage, and hence on the performance of the device. It is disclosed in the present invention a method of forming polysilicon gates where dopant depletion at the interface near the gate oxide layer is alleviated substantially by using laser annealing; however, by first pre-amorphizing the polycrystalline silicon prior to ion (implantation to a desired depth such that during laser annealing the dopants will diffuse uniformly to a melt depth.