摘要:
The invention describes three embodiments of methods for forming a balloon shaped STI trench. The first embodiment begins by forming a barrier layer over a substrate. An isolation opening is formed in the barrier layer. Next, ions are implanted into said substrate through said isolation opening to form a Si damaged or doped first region. The first region is selectively etching to form a hole. The hole is filled with an insulating material to form a balloon shaped shallow trench isolation (STI) region. The substrate has active areas between said balloon shaped shallow trench isolation (STI) regions. The second embodiment differs from the first embodiment by forming a trench in the substrate before the implant. The third embodiment forms a liner in the trench before an isotropic etch of the substrate through the trench.
摘要:
A method of fabricating an air-gap spacer of a semiconductor device, comprising the following steps. A semiconductor substrate having at least a pair of STIs defining an active region is provided. A gate electrode is formed on the substrate within the active region. The gate electrode having an underlying gate dielectric layer. A liner oxide layer is formed over the structure, covering the sidewalls of the gate dielectric layer, the gate electrode, and over the top surface of the gate electrode. A liner nitride layer is formed over the liner oxide layer. A thick oxide layer is formed over the structure. The thick oxide, liner nitride, and liner oxide layers are planarized level with the top surface of the gate electrode, and exposing the liner oxide layer at either side of the gate electrode. The planarized thick oxide layer is removed with a portion of the liner oxide layer and a portion of the gate dielectric layer under the gate electrode to form a cross-section inverted T-shaped opening on either side of the gate electrode. A gate spacer oxide layer is formed over the structure at least as thick as the gate electrode, wherein the gate spacer oxide layer partially fills the inverted T-shaped opening from the top down and wherein air gap spacers are formed proximate the bottom of the inverted T-shaped opening. The gate spacer oxide, liner nitride, and liner oxide layers are etched to form gate spacers proximate the gate electrode. The gate spacers having an underlying etched liner nitride layer and liner oxide layer.
摘要:
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. A gate conductor layer is formed on the gate dielectric layer, filling the gate trench.
摘要:
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.
摘要:
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.
摘要:
A method for forming a sub-quarter micron MOSFET having an elevated source/drain structure is described. A gate electrode is formed over a gate dielectric on a semiconductor substrate. Ions are implanted into the semiconductor substrate to form lightly doped regions using the gate electrode as a mask. Thereafter, dielectric spacers are formed on sidewalls of the gate electrode. A polysilicon layer is deposited overlying the semiconductor substrate, gate electrode, and dielectric spacers wherein the polysilicon layer is heavily doped. The polysilicon layer is etched back to leave polysilicon spacers on the dielectric spacers. Dopant is diffused from the polysilicon spacers into the semiconductor substrate to form source and drain regions underlying the polysilicon spacers. The polysilicon spacer on an end of the gate electrode is removed to separate the polysilicon spacers into a source polysilicon spacer and a drain polysilicon spacer thereby completing formation of a MOSFET having an elevated source/drain structure in the fabrication of an integrated circuit device.
摘要:
A method of fabricating an isolated vertical transistor comprising the following steps. A wafer having a first implanted region selected from the group comprising a source region and a drain region is provided. The wafer further includes STI areas on either side of a center transistor area. The wafer is patterned down to the first implanted region to form a vertical pillar within the center transistor area using a patterned hardmask. The vertical pillar having side walls. A pad dielectric layer is formed over the wafer, lining the vertical pillar. A nitride layer is formed over the pad dielectric layer. The structure is patterned and etched through the nitride layer and the pad dielectric layer; and into the wafer within the STI areas to form STI trenches within the wafer. The STI trenches are filled with insulative material to form STIs within STI trenches. The patterned nitride and pad dielectric layers are removed. The patterned hardmask is removed. Gate oxide is grown over the exposed portions of the wafer and the vertical pillar. Spacer gates are formed over the gate oxide lined side walls of the vertical pillar. Spacer gate implants are formed within the spacer gates, and a second implanted region is formed within the vertical pillar selected from the group consisting of a drain region and a source region that is not the same as the first implanted region to complete formation of the isolated vertical transistor.
摘要:
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.
摘要:
An improved MOS transistor and method of making an improved MOS transistor. An MOS transistor having a recessed source drain on a trench sidewall with a replacement gate technique. Holes are formed in the shallow trench isolations, which exposes sidewall of the substrate in the active area. Sidewalls of the substrate are doped in the active area where holes are. Conductive material is then formed in the holes and the conductive material becomes the source and drain regions. The etch stop layer is then removed exposing sidewalls of the conductive material, and oxidizing exposed sidewalls of the conductive material is preformed. Spacers are formed on top of the pad oxide and on the sidewalls of the oxidized portions of the conductive material. The pad oxide layer is removed from the structure but not from under the spacers. A gate dielectric layer is formed on the substrate in the active area between the spacers; and a gate electrode is formed on said gate dielectric layer.
摘要:
A method to form a MOS transistor with a narrow channel regions and a wide top (second) gate portion. A gate dielectic layer and a first gate layer are formed over a substrate. A second gate portion is formed over the first gate layer. Spacers are formed on the sidewalls of the second gate portion. In a critical step, we isotropically etch the first gate layer to undercut the second gate portion to form a first gate portion so that the first portion has a width less than the second gate portion. The spacers are removed. Lightly doped drains, sidewall spacers and source/drain regions are formed to complete the device.