Abstract: A structure of metal contact portion of a semiconductor device, includes a semiconductor substrate having an impurity doped junction therein, an insulating layer pattern formed on the semiconductor substrate having a contact hole through the insulating layer pattern to expose the doped junction, a conductive projection formed directly on a portion of the doped junction, and a metal layer formed on opposite sides of the conductive projection and contacting the doped junction and the conductive projection, whereby a contact area for the doped junction is increased.
Abstract: According to the present invention, a method for fabricating vertical circuit devices which include a body contact is disclosed. During the fabrication process, the body of a transistor is formed from a pillar of single crystal silicon. The silicon pillar is formed over a butted junction of N+ and P+ diffusions. This fabrication process results in a pillar structure which has an n+ diffusion contacting a portion of the base of the transistor body and a P+ diffusion contacting the remainder of the base of the transistor body. The proportion of N+ and P+ area at the base of the silicon pillar depends on the overlay of the opening to the butted junction. Gate oxide is grown over the entire pillar and a polysilicon gate material is then deposited and etched to form the transistor gate. Metal contact studs are formed, preferably via deposition. After fabrication, the entire surface of the device can be planarized by using any standard Chemical Mechanical Planarization (CMP) process.
Type:
Grant
Filed:
January 28, 1998
Date of Patent:
February 1, 2000
Assignee:
International Business Machines Corporation
Inventors:
Jeffrey Peter Gambino, Jack Allan Mandelman, Stephen Anthony Parke, Matthew Robert Wordeman
Abstract: A vertical field effect transistor (1) and a method of manufacturing thereof are disclosed, in which a buried layer (3) of a conduction type opposite to that of a substrate (2) is formed to a predetermined depth in the substrate (2) by ion implantation. The bottom of recess (2a) for forming a protrusion (2b) on the substrate (2) is located within the corresponding one of the buried layer (3). The width of the recess (2a) is set smaller than the width of the buried layer (3). The surface of the protrusion (2b) and the bottom of the recess (2a) are formed with impurities regions (4a, 4b; 5a, 5b) constituting a source and a drain, respectively. A channel length (L) of the channel region formed on the side wall of the protrusion (2b) is defined by the distance between the buried layer (3) and the impurities regions (5a, 5b) on the surface of the protrusion (2b).
Abstract: A method for forming a trench transistor structure begins by forming a buried layers (12 and 16) and a doped well (22) in a substrate (10) via epitaxial growth processing. A trench region (24) is then etched into the substrate (10) to expose a the layer (12). A conductive sidewall spacer (28) is formed within the trench (24) as a gate electrode. The spacer (28) gates a first transistor (12, 28, 32) located adjacent a first half of the trench (24) and a second transistor (12, 28, 34) located adjacent a second half of the trench (24). Region (12) is a common electrode wherein the channel regions of both the first and second transistor are coupled in a serial manner through the region (12).
Abstract: A process is provided for fabricating MODFET's in group III nitride compound semiconductors. The process precedes isolation of the MODFET structure with the use of e-beam lithography to define very narrow (e.g., .about.0.25 micrometer) gates which enhance transistor microwave cut-off frequency. Because these compound semiconductors resist chemical etchants, isolation is accomplished by etching with reactive ions to form an isolation mesa having a vertical mesa sidewall. To improve breakdown, the mesa sidewall is covered with a passivation layer prior to deposition of a gate feed that contacts the gate. To reduce parasitic gate capacitance, the gate feed is spaced from a narrow edge of the transistor's two-dimensional electron gas.
Type:
Grant
Filed:
April 10, 1997
Date of Patent:
January 5, 1999
Assignee:
Hughes Electronics Corporation
Inventors:
Chanh N. Nguyen, Nguyen Xuan Nguyen, Minh V. Le
Abstract: A method of aligning a gate and a source of a silicon carbide static induction transistor comprising the steps of depositing an oxide layer over the transistor, forming oxide spacers from the oxide layer where the oxide spacers are adjacent the source, depositing a metal layer over the transistor and removing the oxide spacers so that the resulting gates are accurately aligned with the source.
Type:
Grant
Filed:
July 30, 1996
Date of Patent:
September 15, 1998
Assignee:
Northrop Grumman Corporation
Inventors:
Li-Shu Chen, Rowland C. Clarke, Richard R. Siergiej
Abstract: A JFET device is formed on a semiconductor body comprising an active region for the junction field effect device. A drain region layer is formed below the lower portion of the active region. The top surface of the body is doped to provide a source region layer on the device. Gate trenches extend through the source region layer forming source regions therein. The gate trenches also extend partially through the epitaxial layer. The gate trenches have sidewalls and bottoms. Dielectric spacer layers cover the sidewalls of the gate trenches upon surfaces of the source layer and the epitaxial layer in the gate trenches. Self-aligned gate regions are formed at the bottoms of the gate trenches in doped portions of the active region.