Michael S Welch

US Patent:

6387288, May 14, 2002

Filed:

Apr 21, 2000

Appl. No.:

09/556951

Inventors:

Claes Bjorkman - Mountain View CA
Hongching Shan - San Jose CA
Michael Welch - Livermore CA

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01L 21302

US Classification:

216 67, 216 79, 216 80, 438711, 438729

Abstract:

An apparatus and method for scavenging etchant species from a plasma formed of etchant gas prior to the etchant gas entering a primary processing chamber of a plasma reactor. There is at least one scavenging chamber, each of which is connected at an inlet thereof to an etchant gas source and at an outlet thereof to a gas distribution device of the primary processing chamber. Each scavenging chamber has a radiation applicator that irradiates the interior of the scavenging chamber and creates a plasma therein from etchant gas flowing through the chamber from the etchant gas source to the gas distribution apparatus of the primary processing chamber. The applicator uses either an inductive discharge, capacitive discharge, direct current (DC) discharge or microwave discharge to irradiate the interior of the scavenging chamber and ignite the plasma. An etchant species scavenging source is also disposed within the scavenging chamber. This source provides scavenging material that interacts with the plasma to scavenge etchant species created by the dissociation of the etchant gas in the plasma and form etch by-products comprised of substances from both the etchant species and the scavenging source.

US Patent:

6391790, May 21, 2002

Filed:

Jul 25, 2000

Appl. No.:

09/625343

Inventors:

Brigitte C. Stoehr - San Jose CA
Michael D. Welch - Livermore CA

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01L 2100

US Classification:

438715, 216 67, 216 75, 216 79, 438720, 438723, 438742

Abstract:

A process is provided for etching a silicon based material in a substrate, such as a photomask, to form features with straight sidewalls, flat bottoms, and high profile angles between the sidewalls and bottom, and minimizing the formation of polymer deposits on the substrate. In the etching process, the substrate is positioned in a processing chamber, a processing gas comprising a fluorocarbon, which advantageously is a hydrogen free fluorocarbon, is introduced into the processing chamber, wherein the substrate is maintained at a reduced temperature, and the processing gas is excited into a plasma state at a reduced power level to etch the silicon based material of the substrate. The processing gas may further comprise an inert gas, such as argon.

US Patent:

6432259, Aug 13, 2002

Filed:

Dec 14, 1999

Appl. No.:

09/461682

Inventors:

Hamid Noorbakhsh - Fremont CA
Michael Welch - Livermore CA
Siamak Salimian - Sunnyvale CA
Paul Luscher - Sunnyvale CA
Hongching Shan - San Jose CA
Kaushik Vaidya - Sunnyvale CA
Jim Carducci - Sunnyvale CA
Evans Lee - Milpitas CA

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H05H 100

US Classification:

15634533, 15634534, 15634544, 118724, 118723 E

Abstract:

A plasma reactor embodying the invention includes a wafer support and a chamber enclosure member having an interior surface generally facing the wafer support. At least one miniature gas distribution plate for introducing a process gas into the reactor is supported on the chamber enclosure member and has an outlet surface which is a fraction of the area of the interior surface of said wafer support. A coolant system maintains the chamber enclosure member at a low temperature, and the miniature gas distribution plate is at least partially thermally insulated from the chamber enclosure member so that it is maintained at a higher temperature by plasma heating.

US Patent:

6513452, Feb 4, 2003

Filed:

Apr 24, 2001

Appl. No.:

09/841804

Inventors:

Hongching Shan - San Jose CA
Evans Y. Lee - Milpitas CA
Michael D. Welch - Livermore CA
Robert W. Wu - Pleasanton CA
Bryan Y. Pu - San Jose CA
Paul E. Luscher - Sunnyvale CA
James D. Carducci - Sunnyvale CA
Richard Blume - San Jose CA

Assignee:

Applied Materials Inc. - Santa Clara CA

International Classification:

C23C 1600

US Classification:

118723E, 118715, 15634543

Abstract:

A method of adjusting the cathode DC bias in a plasma chamber for fabricating semiconductor devices. A dielectric shield is positioned between the plasma and a selected portion of the electrically grounded components of the chamber, such as the electrically grounded chamber wall. The cathode DC bias is adjusted by controlling one or more of the following parameters: (1) the surface area of the chamber wall or other grounded components which is blocked by the dielectric shield; (2) the thickness of the dielectric; (3) the gap between the shield and the chamber wall; and (4) the dielectric constant of the dielectric material. In an apparatus aspect, the invention is a plasma chamber for fabricating semiconductor devices having an exhaust baffle with a number of sinuous passages. Each passage is sufficiently long and sinuous that no portion of the plasma within the chamber can extend beyond the outlet of the passage. By blocking the plasma from reaching the exhaust pump, the exhaust baffle reduces the deposition of unwanted particles on exhaust pump components.

US Patent:

6534417, Mar 18, 2003

Filed:

Apr 19, 2002

Appl. No.:

10/126851

Inventors:

Brigitte C. Stoehr - San Jose CA
Michael D. Welch - Pleasanton CA

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01L 2100

US Classification:

438715, 438720, 438723, 438742, 438724, 438744

Abstract:

A process is provided for etching a silicon based material in a substrate, such as a photomask, to form features with straight sidewalls, flat bottoms, and high profile angles between the sidewalls and bottom, and minimizing the formation of polymer deposits on the substrate. In the etching process, the substrate is positioned in a processing chamber, a processing gas comprising a fluorocarbon, which advantageously is a hydrogen free fluorocarbon, is introduced into the processing chamber, wherein the substrate is maintained at a reduced temperature, and the processing gas is excited into a plasma state at a reduced power level to etch the silicon based material of the substrate. The processing gas may further comprise an inert gas, such as argon.

US Patent:

6592673, Jul 15, 2003

Filed:

May 27, 1999

Appl. No.:

09/322102

Inventors:

Michael D. Welch - Livermore CA
Harald Herchen - San Jose CA

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

B05C 1100

US Classification:

118676, 118715, 118668, 118728, 15634524, 15634551

Abstract:

A chamber comprises a support for holding a substrate and a sensor system adapted to detect the presence or proper placement of the substrate on the support. The support comprises a window that is transparent and adapted to transmit light therethrough. The sensor system comprises a light source adapted to direct a light beam through the window and a light sensor in the path of the light beam. The light beam is sensed by the light sensor when the substrate is properly positioned and the light beam is blocked from the light sensor when the substrate is improperly positioned or vice versa. Preferably, the support comprises an electrostatic chuck adapted to electrostatically hold the substrate , the electrostatic chuck comprising a window composed of transparent material or a cut-out or a hole therein.

US Patent:

6647918, Nov 18, 2003

Filed:

Nov 13, 2000

Appl. No.:

09/711191

Inventors:

Michael D. Welch - Livermore CA
Paul E. Luscher - Sunnyvale CA
Evans Y. Lee - Milpitas CA
James D. Carducci - Sunnyvale CA
Siamak Salimian - Sunnyvale CA

Assignee:

Applied Materials, Inc - Santa Clara CA

International Classification:

C23C 1600

US Classification:

118723R, 118715, 118723 E, 118733, 15634531, 15634532, 15634543, 156916

Abstract:

In a substrate vacuum processing chamber, a second inner slit passage door apparatus and method to supplement the normal slit valve and its door at the outside of the chamber. The inner slit passage door, blocks the slit passage at or adjacent the substrate processing location in a vacuum processing chamber to prevent process byproducts from depositing on the inner surfaces of the slit passage beyond the slit passage door and improves the uniformity of plasma in the processing chamber by eliminating a large cavity adjacent to the substrate processing location into which the plasma would otherwise expand. The inner slit passage door is configured and positioned in such a way as to avoid generating particles from the opening and closing motion of the second slit valve door, as it does not rub against any element of the chamber during its motion and the inner slit passage door is positioned with a predetermined gap from adjacent pieces and the door configuration includes beveled surfaces to further reduce the chance for particle generation, even when there is deposition of process byproducts on the door and its adjacent surfaces.

US Patent:

6689249, Feb 10, 2004

Filed:

Sep 4, 2001

Appl. No.:

09/947194

Inventors:

Bryan Y. Pu - San Jose CA
Hongching Shan - San Jose CA
James Wang - Saratoga CA
Henry Fong - Daly City CA
Zongyu Li - Sunnyvale CA
Michael D. Welch - Livermore CA

Assignee:

Applied Materials, Inc - Santa Clara CA

International Classification:

C23F 108

US Classification:

1563453, 313240, 118504

Abstract:

A ring or collar surrounding a semiconductor workpiece in a plasma chamber. According to one aspect, the ring has an elevated collar portion having an inner surface oriented at an obtuse angle to the plane of the workpiece, this angle preferably being 135Â. This angular orientation causes ions bombarding the inner surface of the elevated collar to scatter in a direction more parallel to the plane of the workpiece, thereby reducing erosion of any dielectric shield at the perimeter of the workpiece, and ameliorating spatial non-uniformity in the plasma process due to any excess ion density near such perimeter. In a second aspect, the workpiece is surrounded by a dielectric shield, and the shield is covered by a non-dielectric ring which protects the dielectric shield from reaction with, or erosion by, the process gases. In a third aspect, the dielectric shield is thin enough to couple substantial power from the cathode to the plasma, thereby improving spatial uniformity of the plasma process near the perimeter of the workpiece. In a fourth aspect, azimuthal non-uniformities in process performance can be ameliorated by corresponding azimuthal variations in the dimensions of the elevated collar and/or the dielectric shield surrounding the workpiece.