摘要:
A method to form a closely-spaced, vertical NMOS and PMOS transistor pair in an integrated circuit device is achieved. A substrate comprises silicon implanted oxide (SIMOX) wherein an oxide layer is sandwiched between underlying and overlying silicon layers. Ions are selectively implanted into a first part of the overlying silicon layer to form a drain, channel region, and source for an NMOS transistor. The drain is formed directly overlying the oxide layer, the channel region is formed overlying the drain, and the source is formed overlying the channel region. Ions are selectively implanted into a second part of the overlying silicon layer to form a drain, channel region, and source for a PMOS transistor. The drain is formed directly overlying the oxide layer, the PMOS channel region is formed overlying the drain, and the source is formed overlying the channel region. The PMOS transistor drain is in contact with said NMOS transistor drain. A gate trench is etched through the NMOS and PMOS sources and channel regions. The gate trench terminates at the NMOS and PMOS drains and exposes the sidewalls of the NMOS and PMOS channel regions. A gate oxide layer is formed overlying the NMOS and PMOS channel regions and lining the gate trench. A polysilicon layer is deposited and etched back to form polysilicon sidewalls and to thereby form gates for the closely-spaced, vertical NMOS and PMOS transistor pair.
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 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. The microtrench is filled with an epitaxial oxide layer and planarized to the hard mask layer. The dielectric layer is patterned to form third spacers on the epitaxial oxide layer. The microtrench reduces the effective dielectric constant at the overlap between the gate and the source/drain extensions to complete formation of a transistor having low overlap capacitance.
摘要:
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.
摘要:
A method to form elevated source/drain (S/D) over staircase shaped openings in insulating layers. A gate structure is formed over a substrate. The gate structure is preferably comprised of a gate dielectric layer, gate electrode, first spacers, and hard mask. A first insulating layer is formed over the substrate and the gate structure. A resist layer is formed having an opening over the gate structure and over a lateral area adjacent to the gate structure. We etch the insulating layer through the opening in the resist layer. The etching removes a first thickness of the insulating layer to form a source/drain (S/D) opening. We remove the first spacers and hardmask to form a source/drain (S/D) contact opening. We implant ions into the substrate through the source/drain (S/D) contact opening to form lightly doped drain regions. We form second spacers on the sidewalls of the gate electrode and the gate dielectric and on the sidewalls of the insulating layer in the source/drain (S/D) contact opening and the source/drain (S/D) opening. A conductive layer is deposited over the gate electrode, the insulating layer. The conductive layer is planarized to exposed the insulating layer to form elevated source/drain (S/D) blocks on a staircase shape insulating layer.
摘要:
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. A channel length is between the top of the source region and the drain region. We form an interlevel dielectric layer over the barrier layer, the gate layer, and the conductive plug. Contacts are formed through the interlevel dielectric layer to the doped gate regions, the drain region and the source region.
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 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.