International Business Machines Corporation

Xiaowei Tian

Minh H Tong

Edward J Nowak

Robert Mark Rassel

Xuefeng Liu

Richard A Phelps

Robert J Gauthier, Jr

Steven H Voldman

Jeffrey Scott Brown

Stephen Scott Furkay

William R Tonti

Howard L Kalter

Disclosed are embodiments of a junction field effect transistor (JFET) structure with one or more P-type silicon germanium (SiGe) or silicon germanium carbide (SiGeC) gates (i.e., a SiGe or SiGeC based heterojunction JFET). The P-type SiGe or SiGeC gate(s) allow for a lower pinch off voltage (i.e., lower Voff) without increasing the on resistance (Ron). Specifically, SiGe or SiGeC material in a P-type gate limits P-type dopant out diffusion and, thereby ensures that the P-type gate-to-N-type channel region junction is more clearly defined (i.e., abrupt as opposed to graded). By clearly defining this junction, the depletion layer in the N-type channel region is extended. Extending the depletion layer in turn allows for a faster pinch off (i.e., requires lower Voff). P-type SiGe or SiGeC gate(s) can be incorporated into conventional lateral JFET structures and/or vertical JFET structures. Also disclosed herein are embodiments of a method of forming such a JFET structure.

Junction field effect transistor structure with P-type silicon germanium or silicon germanium carbide gate(s) and method of forming the structure

A junction gate field-effect transistor (JFET) for an integrated circuit (IC) chip is provided comprising a source region, a drain region, a lower gate, and a channel, with an insulating shallow trench isolation (STI) region extending from an inner edge of an upper surface of the source region to an inner edge of an upper surface of the drain region, without an intentionally doped region, e.g., an upper gate, coplanar with an upper surface of the IC chip between the source/drain regions. In addition, an asymmetrical quasi-buried upper gate can be included, disposed under a portion of the STI region, but not extending under a portion of the STI region proximate to the drain region. Embodiments of this invention also include providing an implantation layer, under the source region, to reduce R. A related method and design structure are also disclosed.

Asymmetric wedge JFET, related method and design structure

A structure and process for making a non-aligned MOSFET structure for ESD protection using resistor wells as the diffusions and adjustable capacitors. The present invention compensates the shallow extension region without the need for additional masks. The source/drain doping is less than that of a normal MOSFET but extends deeper into the silicon since the present invention uses a resistor well as the source/drain. The deeper emitter/collector increases the second trigger current of the NFET when used as an ESD protection device.

Diffusion resistor/capacitor (DRC) non-aligned MOSFET structure

A diffusion resistor is provided that utilizes the block mask to cover only the intrinsic polysilicon gate region. The n-type source/drain doping is implanted in the contact regions, but not in the intrinsic polysilicon gate region. A N-type (or P-type) diffusion resistor in P-well (or N-well) is provided that utilizes a block mask to cover only the intrinsic polysilicon gate region. The N-type (or P-type) source/drain doping is implanted in the contact regions but not in the intrinsic polysilicon gate region. The P-well (or N-well) block mask is used to keep the P-well (or N-well) from forming under the buried resistor. This makes the parasitic capacitance of the diffusion junction very low. Also provided is a buried capacitor and method of making both a buried resistor and a buried capacitor.

Reliable diffusion resistor and diffusion capacitor

A semiconductor device and method of fabrication for such device in which a P- epitaxial layer is positioned above a P++ substrate. A P++ buried layer implant is positioned within the device between the P++ substrate and the P- epitaxial layer. A connecting p+ implant is placed within the epitaxial layer above the buried p+ blanket layer implant. In one exemplary embodiment, the device includes a shallow P-well with the P+ connecting implant in a position within the epitaxial layer connecting the shallow P-well and the buried P+ blanket implant layer.

Semiconductor device fabrication method and apparatus using connecting

A noise-isolated buried resistor satisfies the requirements for low-noise analog designs requiring well controlled ohmic resistors. A field shield is provided between the buried resistor and the substrate to isolate the buried resistor from the substrate noise. This is accomplished by using the standard buried resistor layout and mask sequence with two exceptions. First, the buried resistor is placed in an N-well region, rather than simply a P-well region. Second, a boron implant is added through the buried resistor mask to provide a P-well inside the N-well to isolate the buried resistor electrically from the N-well. The N-well may then be electrically connected to a 'quiet' ground. The P-well inside of the N-well may be left floating.

Method of making a noise-isolated buried resistor by implanting a first

Semiconductor device fabrication method using connecting implants

A method of forming a self-aligned halo-isolated well with a single mask is disclosed. First, a layer of resist is disposed over at least a portion of a substrate's surface. Then, an impurity of a first polarity type is implanted at an angle into the substrate through a gap in the layer of resist, thus forming a well having the impurity of the first polarity, which extends beneath the layer of resist. An impurity of a second polarity type is also implanted, using the same mask as previously used. The second implantation forms a well of the impurity of the second polarity disposed within the well of to impurity of the first polarity.

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Essex, VT, United States of America

Xiaowei Tian