Han M Xu, 6110 Winchester Dr, Lexington, MA 02420

6479396, Nov 12, 2002

Feb 28, 2001

09/794055

Han Xu - Lexington MA
Amy Ying Shen - Wakefield MA

Infineon Technologies Richmond, LP - Sandston VA

H01L 2100

438723, 216 67, 216 75, 216 79, 438720, 438725, 438734, 438743, 438742

In a process of preparing a via in a semiconductor substrate wafer in which vias are landed on tungsten, and in which resist is stripped using plasma or chemical based processes that do not remove the veils formed during the etch, the improvement of concurrently removing veil material, controlling the interface of the tungsten, and stripping the resist, comprising: a) depositing and patterning tungsten on a substrate; b) depositing an oxide as an interlevel dielectric on the tungsten; c) patterning the oxide using photolithography and a photoresist; d) etching the oxide using a plasma generated etching method in which veils made up of metals, carbon based materials and oxide based materials are formed on the tungsten and sidewalls of the vias; and e) stripping the resist using a dry polymer removal method employing process gases and reducing gases to concurrently cause resist stripping, removal of the veils, and control of the tungsten interface.

5882489, Mar 16, 1999

Apr 26, 1996

8/638279

Richard L. Bersin - Lawrence MA
Han Xu - Lexington MA

Ulvac Technologies, Inc. - Methuen MA

C23C 1434
C23F 100
H01L 213065

20419235

A method for removing a resist layer, particularly in via holes, includes plasma to remove organic compounds, rinsing the device in deionized water, and sputtering with argon to remove inorganic compounds. The order of rinsing and sputtering can be reversed. These methods avoid the use of acids and industrial solvents.

5908319, Jun 1, 1999

Apr 24, 1996

8/637137

Han Xu - Lexington MA
Richard L. Bersin - Lawrence MA

ULvac Technologies, Inc. - Methuen MA

H01L 21302

438725

In a microwave downstream process, a microwave plasma is formed from a gas that has a small quantity of fluorine to enhance ashing without substantial oxide loss. This process can be performed before or after other microwave downstream processes or reactive ion etching processes.

5795831, Aug 18, 1998

Oct 16, 1996

8/731612

Izumi Nakayama - Groton MA
Yukio Masuda - North Andover MA
Richard L. Bersin - Boxford MA
Han Xu - Lexington MA
Quain Geng - Acton MA

Ulvac Technologies, Inc. - Andover MA

C23F 102

438714

A method for removing a resist layer includes an RIE process and a downstream microwave process, each performed such that the temperature of the wafer is no greater than about 60. degree. C. By performing these processes cold, the resist need not be pre-heated to drive off solvents. The RIE process and the microwave process can be performed sequentially or simultaneously.

6083413, Jul 4, 2000

Oct 1, 1998

9/051686

Herbert H. Sawin - Chestnut Hill MA
Jane P. Chang - Cambridge MA
Andrew Scott Lawing - Phoenix AZ
Zhe Zhang - Irvine CA
Han Xu - Lexington MA

Massachusetts Institute of Technology - Cambridge MA

B44C 122

216104

A process for removing metallic material, for instance copper, iron, nickle and their oxides, from a surface of a substrate such as a silicon, silicon oxide or gallium arsenide substrate. The process includes the steps of: a) placing the substrate in a reaction chamber; b) providing in the reaction chamber a gas mixture, the mixture comprising a first component which is fluorine or a fluorine-containing compound, which will spontaneously dissociate upon adsorption on the substrate surface and a second component which is a halosilane compound, the halosilane, and the fluorine if present, being activated by: i) irradiation with UV; ii) heating to a temperature of about 800. degree. C. or higher; or iii) plasma generation, to thereby convert said metallic material to a volatile metal-halogen-silicon compound, and c) removing the metal-halogen-silicon compound from the substrate by volatilization. The process may be used to remove both dispersed metal and bulk metal films or islands.