International Business Machines Corporation

Reid S Bennett

Gary S Selwyn

Jyothi Singh

George G Gifford

Kurt L Haller

Albert R Ellingboe

John S McKillop

Geraldine C Schwartz

Dennis S Yee

Linda M Ephrath

A self-aligned method of forming contacts to a transistor gate, source and drain reduces the required spacing between the nominal center of the gate and electrode at little cost in process complexity by the provision of a sidewall positioned above the LDD-defining sidewall and extending above the top Of the gate by a buffer amount sufficient to protect the gate during the process of opening a source or drain contact.

Simplified contact method for high density CMOS

Contamination levels in plasma processes are reduced during plasma processing, by prevention of formation of particles, by preventing entry of particles externally introduced or by removing particles spontaneously formed from chemical and/or mechanical sources. Some techniques for prevention of formation of particles include interruption of the plasma by pulsing the source of plasma energy periodically, or application of energy to provide mechanical agitation such as mechanical shockwaves, acoustic stress, ultrasonic stress, vibrational stress, thermal stress, and pressure stress. Following a period of applied stress, a tool is pumped out (if a plasma is used, the glow is first discontinued), vented, opened and flaked or particulate material is cleaned from the lower electrode and other surfaces. A burst of filtered air or nitrogen, or a vacuum cleaner is used for removal of deposition debris while the vented tool is open. Following this procedure, the tool is then be used for product runs. Alternatively, improvement of semiconductor process yields can be achieved by addition of reagents to getter chemical precursors of contamination particulates and by filtration of particulates from feedgas before plasma processing. The efficiency and endpoint for the applied stress are determined, by laser light scattering, using a pulsed or continuous laser source, e.g. a HeNe laser.

Methods and apparatus for contamination control in plasma processing

Contamination levels in plasma processes are reduced during plasma processing, by prevention of formation of particles, by preventing entry of particles externally introduced or by removing particles spontaneously formed from chemical and/or mechanical sources. Some techniques for prevention of formation of particles include interruption of the plasma by pulsing the source of plasma energy periodically, or application of energy to provide mechanical agitation such as mechanical shockwaves, acoustic stress, ultrasonic stress, vibrational stress, thermal stress, and pressure stress. Following a period of applied stress, a tool is pumped out (if a plasma is used, the glow is first discontinued), vented, opened and flaked or particulate material is cleaned from the lower electrode and other surfaces. A burst of filtered air or nitrogen, or a vacuum cleaner is used for removal of deposition debris while the vented tool is open.

Laser induced fluorescence is utilized to detect and control the reactive ion etch-through of a given layer in a wafer by detecting a large change in the concentration of a selected minor species from the wafer in the etching plasma. This selected minor species must be present in a significantly different concentration in the etched given layer compared to adjacent layers in the wafer in order to provide a proper endpoint detection. In one embodiment, when the large change in the selected minor species concentration is detected, then the RF electrodes for the reactor are automatically de-energized.

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Wappingers Falls, NY, United States of America

Reid S Bennett