Geoffrey W Crabtree

US Patent:

20110120365, May 26, 2011

Filed:

Nov 25, 2009

Appl. No.:

12/626180

Inventors:

Hui She - Issaquah WA, US
Geoffrey Crabtree - Vancouver WA, US

International Classification:

C30B 11/00
C01B 33/037

US Classification:

117 74, 423349, 117206

Abstract:

A process for removal of contaminants from a melt of non-ferrous metals comprising the following steps: providing an apparatus () for melting and solidifying non-ferrous metals comprising a crucible () for holding a non-ferrous metal melt and a process chamber (), in which the crucible () can be placed, wherein the crucible () contains an additive (), providing a melt () in the crucible (), heating the melt () in the crucible () to a predetermined temperature, whereby the additive () can react with contaminants in the melt (), and segregating the reacted contaminants from the melt ().

US Patent:

55535666, Sep 10, 1996

Filed:

Jun 22, 1995

Appl. No.:

8/493607

Inventors:

Geoffrey J. Crabtree - Chandler AZ

Assignee:

Motorola Inc. - Schaumburg IL

International Classification:

C30B 1504

US Classification:

117 2

Abstract:

A method for fabricating semiconductor substrates with resistivity below 0. 02 ohm-cm is provided. This low resistivity is achieved by doping a silicon melt with a phosphorus concentrations above 1. times. 10. sup. 18. The silicon melt is also doped with a germanium concentration that is 1. 5 to 2. 5 times that of the phosphorus concentration and a stress and dislocation free crystalline boule is grown. Phosphorus in high concentrations will induce stress in the crystal lattice due to the difference in the atomic radius of silicon atoms versus phosphorus atoms. Germanium compensates for the atomic radius mismatch and also retards the diffusion of the phosphorus as the diffusion coefficient remains relatively constant with a doping of 1. times. 10. sup. 18 to 1. times. 10. sup. 21 atoms per cm. sup. 3. This will retard phosphorus from diffusing into an overlying epitaxial layer and retard other layers formed on the substrate from being auto-doped.

US Patent:

57443963, Apr 28, 1998

Filed:

May 31, 1996

Appl. No.:

8/658908

Inventors:

Geoffrey J. Crabtree - Chandler AZ

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01L 21225

US Classification:

438501

Abstract:

A method for fabricating semiconductor substrates with resistivity below 0. 02 ohm-cm is provided. This low resistivity is achieved by doping a silicon melt with a phosphorus concentrations above 1. times. 10. sup. 18. The silicon melt is also doped with a germanium concentration that is 1. 5 to 2. 5 times that of the phosphorus concentration and a stress and dislocation free crystalline boule is grown. Phosphorus in high concentrations will induce stress in the crystal lattice due to the difference in the atomic radius of silicon atoms versus phosphorus atoms. Germanium compensates for the atomic radius mismatch and also retards the diffusion of the phosphorus as the diffusion coefficient remains relatively constant with a doping of 1. times. 10. sup. 18 to 1. times. 10. sup. 21 atoms per cm. sup. 3. This will retard phosphorus from diffusing into an overlying epitaxial layer and retard other layers formed on the substrate from being auto-doped.

Address:

830 Pisces Pass St, San Antonio, TX 78260

Phone:

8304382874

VIN:

JTHBJ46G182174286

Make:

LEXUS

Model:

ES 350

Year:

2008