International Business Machines Corporation

Other

Chang-Ming Hsieh

Louis L Hsu

Seiki Ogura

Klaus D Beyer

Shaw-Ning Mei

Brian H Desilets

Lawrence F Wagner, Jr

Ronald W Knepper

Taqi Nasser Buti

Louis Lu-chen Hsu

Jack Allan Mandelman

Peter Anton Habitz

Tsorng-Dih Yuan

Lyndon Ronald Logan

Mario M Pelella

Somnuk Ratanaphanyarat

Kyong-Min Kim

Shao-Fu S Chu

Yi-Shiou Huang

Shao-Fu Sanford Chu

Jack Oon Chu

David Edward Kotecki

Joseph F Shepard

Victor J Silvestri

Paul Andrew Ronsheim

Martin Revitz

Phung T Nguyen

Victor R Nastasi

Robert K Cook

Zu-Jean Tien

Toshio Mii

Kiyosi Isihara

Shantha A Kumar

Tsoring-Dih Yuan

A field effect transistor (FET) device, which mitigates leakage current induced along the edges of the FET device, is isolated by shallow trench isolation having a channel width between a first and a second shallow trench at a first and second shallow trench edges. A gate extends across the channel width between the first and second shallow trenches. The gate has a first length at the shallow trench edges and a second length less than the first length between the shallow trench edges. The first length and the second length are related such that the threshold voltage, V.sub.t, at the shallow trench edges is substantially equal to V.sub.t between the shallow trench edges. The gate structure of the FET device is produced using a unique phase shift mask that allows the manufacture of submicron FET devices with very small channel lengths.

Method to suppress subthreshold leakage due to sharp isolation corners

An EEPROM cell includes a dual-gate transistor having a floating gate for storing the data and a select gate to access the cell, the two gates each being formed from poly sidewalls and being separated by a thin vertical oxide member that is formed by growing oxide on the vertical poly sidewalls of an aperture in which the select gate is formed, so that the final structure has dimensions that are less than those obtainable with optical lithography because both gates are sidewalls and therefore not limited to the dimensions achievable with optical lithography.

Flash EEPROM

SOI Transistor Having a Self-aligned Body Contact An SOI transistor has a self-aligned body contact formed through an extension to the gate, thereby forming the body contact with minimal increase in area and also avoiding the need to tie the source to the body, as in prior art schemes that passed the body contact through the source. The body contact aperture is formed by raising the source and drain to define an initial aperture, depositing a conformal layer that is etched to create aperture-defining sidewalls and etching the contact aperture using these sidewalls to define sidewall support members that support insulating sidewalls to isolate the collection electrode from both the gate and from the source and drain.

SOI transistor having a self-aligned body contact

Flash EEPROM with dual-sidewall gate

An improved design for high aspect ratio MOS devices is capable of 100% yields. The design is suitable for low voltage CMOS devices, such as microprocessors, which use the high aspect ratio MOS devices in embedded applications, and for HEMTs in high frequency applications, such as high power microwave devices. The high yields reduce manufacturing costs. A modular MOS concept is introduced to realize the 100% yield of large channel width devices. The structure of the modular MOS device is a regular MOS device with a unit device channel width. This can be a multi-finger device which has a proper dimension to be able to fit in a given layout area. Therefore, the number of modules which are needed to form a full large width device is not only determined by module size, but also on the manufacturing yield record, allowed chip real estate and performance requirement.

Modular MOSFETS for high aspect ratio applications

Modifications of a digital logic device, such as a static or dynamic random access memory (SRAM or DRAM) or pass gate logic circuit or the like, implemented with complementary metal-oxide-semiconductor (CMOS) structures formed with silicon-on-insulator (SOI or, more specifically, SOICMOS) technology effectively suppress transient parasitic bipolar current disturbances (e.g. transient half select write disturb instabilities) caused by a discharge current through a parasitic lateral bipolar transistor formed under the transfer gate field effect transistors. Level shifting of the 'off' voltage applied to the gate electrode of the transfer gate transistor dynamically changes the gain of the cell transfer gate to increase memory cell stability without compromising the memory capacity per chip or read/write memory cycle time even though level shifting can greatly increase majority carrier density in the floating body (gate) of a SOICMOS transistor at a particular level shifted voltage range. Alternatively, or additionally, the discharge of deselected cells can be slowed to avoid instability by increasing resistance of the transistors in the data buffer (with saving of chip space) and/or increasing bit line capacitance by increasing bit line length (allowing increased memory array size or an additional cell array on a chip).

Methods to enhance SOI SRAM cell stability

An SOI transistor has a self-aligned body contact formed through an extension to the gate, thereby forming the body contact with minimal increase in area and also avoiding the need to tie the source to the body, as in prior art schemes that passed the body contact through the source. The body contact aperture is formed by raising the source and drain to define an initial aperture, depositing a conformal layer that is etched to create aperture-defining sidewalls and etching the contact aperture using these sidewalls to define sidewall support members that support insulating sidewalls to isolate the collection electrode from both the gate and from the source and drain.

Method of making trimmable modular MOSFETs for high aspect ratio

A high density, DRAM cell array with a very short channel, vertical gate transfer transistor that can be manufactured using conventional photolithography process steps. The conventional four-by-four DRAM array shown schematically in FIG. 1a is rearranged to the shared-gate, double-bit array shown schematically in FIG. 1b. Trench storage capacitors and vertical FET transistors are arranged in pairs with a common vertical gate and a common substrate, allowing both bit and substrate contacts to be shared by adjacent cells.

High-density DRAM structure on soi

A bonded, SOI wafer which has stepped isolation trenches and sublayer interconnections first formed in a bulk silicon wafer. After these process steps are complete, a thin polysilicon layer is formed on the planarized upper surface of the bulk silicon wafer. This thin polysilicon layer is then bound to an oxide layer on the surface of a separate wafer to form a bonded silicon-on-oxide structure. The entire assembly is, in effect inverted, and what had been the lower surface of the bulk silicon wafer, is removed to the bottom of the deepest trench step. In this bonded SOI structure, regions between the trenches are deep and suitable for bipolar device fabrication, while the trench steps form shallow regions suitable for fabrication of CMOS devices.

Advanced silicon on oxide semiconductor device structure for BiCMOS

Method of forming silicon on oxide semiconductor device structure for

Method of making a high-density DRAM structure on SOI

A transistor with silicon on insulator (SOI) intrinsic base and a collector each formed by a low temperature epitaxial process and each orientated vertically with respect to the (SOI) substrate. The base width can be as narrow as in a conventional vertical transistor. Similarly, the collector width can be precisely controlled.

Vertical-gate CMOS compatible lateral bipolar transistor

Method of forming a SOI transistor having a self-aligned body contact

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Fishkill, NY, United States of America

Chang-Ming Hsieh