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Gregory Schaadt Phones & Addresses

  • 1524 Bellomy St, Santa Clara, CA 95050
  • 2272 Benton St, Santa Clara, CA 95050
  • San Jose, CA

Work

Position: Professional/Technical

Education

Degree: High school graduate or higher

Publications

Us Patents

Method For Making A Micromechanical Device By Removing A Sacrificial Layer With Multiple Sequential Etchants

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US Patent:
6800210, Oct 5, 2004
Filed:
May 22, 2002
Appl. No.:
10/154150
Inventors:
Satyadev R. Patel - Elk Grove CA
Andrew G. Huibers - Mountain View CA
Gregory P. Schaadt - Santa Clara CA
Peter J. Heureux - Felton CA
Assignee:
Reflectivity, Inc. - Sunnyvale CA
International Classification:
H01L 21306
US Classification:
216 2, 216 58, 216 79, 438719, 438734, 438706
Abstract:
An etching method, such as for forming a micromechanical device, is disclosed. One embodiment of the method is for releasing a micromechanical structure, comprising, providing a substrate; providing a sacrificial layer directly or indirectly on the substrate; providing one or more micromechanical structural layers on the sacrificial layer; performing a first etch to remove a portion of the sacrificial layer, the first etch comprising providing an etchant gas and energizing the etchant gas so as to allow the etchant gas to physically, or chemically and physically, remove the portion of the sacrificial layer; performing a second etch to remove additional sacrificial material in the sacrificial layer, the second etch comprising providing a gas that chemically but not physically etches the additional sacrificial material. Another embodiment of the method is for etching a silicon material on or within a substrate, comprising: performing a first etch to remove a portion of the silicon, the first etch comprising providing an etchant gas and energizing the etchant gas so as to allow the etchant gas to physically, or chemically and physically, remove the portion of silicon; performing a second etch to remove additional silicon, the second etch comprising providing an etchant gas that chemically but not physically etches the additional silicon.

Etching Method In Fabrications Of Microstructures

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US Patent:
6939472, Sep 6, 2005
Filed:
Sep 17, 2003
Appl. No.:
10/665998
Inventors:
Gregory P. Schaadt - Santa Clara CA,
Hongqin Shi - San Jose CA,
Assignee:
Reflectivity, Inc. - Sunnyvale CA
International Classification:
C23F001/00
US Classification:
216 2, 216 58, 216 59, 216 75, 216 76, 216 77, 216 79, 216 93, 438 5, 438 14, 438706, 427 96
Abstract:
The present invention teaches a method and apparatus for removing sacrificial materials in fabrications of microstructures using one or more selected spontaneous vapor phase etchants. The selected etchant is fed into an etch chamber containing the microstructure during each feeding cycle of a sequence of feeding cycles until the sacrificial material of the microstructure is exhausted through the chemical reaction between the etchant and the sacrificial material. Specifically, during a first feeding cycle, a first amount of selected spontaneous vapor phase etchant is fed into the etch chamber. At a second feeding cycle, a second amount of the etchant is fed into the etch chamber. The first amount and the second amount of the selected etchant may or may not be the same. The time duration of the feeding cycles are individually adjustable.

Method For Achieving Improved Selectivity In An Etching Process

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US Patent:
6942811, Sep 13, 2005
Filed:
Sep 17, 2001
Appl. No.:
09/954864
Inventors:
Satyadev R. Patel - Elk Grove CA,
Gregory P. Schaadt - Santa Clara CA,
Douglas B. MacDonald - Los Gatos CA,
Hongqin Shi - Santa Clara CA,
Assignee:
Reflectivity, Inc - Sunnyvale CA
International Classification:
B81B003/00
US Classification:
216 2, 216 59, 216 72, 216 79
Abstract:
The etching of a sacrificial silicon portion in a microstructure such as a microelectromechanical structure by the use of etchant gases that are noble gas fluorides or halogen fluorides is performed with greater selectivity toward the silicon portion relative to other portions of the microstructure by slowing the etch rate. The etch rate is preferably 30 um/hr or less, and can be 3 um/hr or even less. The selectivity is also improved by the addition of non-etchant gaseous additives to the etchant gas. Preferably the non-etchant gaseous additives that have a molar-averaged formula weight that is below that of molecular nitrogen offer significant advantages over gaseous additives of higher formula weights by causing completion of the etch in a shorter period of time while still achieving the same improvement in selectivity. The etch process is also enhanced by the ability to accurately determine the end point of the removal step. A vapor phase etchant is used to remove a material that has been deposited on a substrate, with or without other deposited structure thereon.

Apparatus And Method For Flow Of Process Gas In An Ultra-Clean Environment

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US Patent:
6949202, Sep 27, 2005
Filed:
Aug 28, 2000
Appl. No.:
09/649569
Inventors:
Satyadev R. Patel - Elk Grove CA,
Gregory P. Schaadt - Santa Clara CA,
Douglas B. MacDonald - Los Gatos CA,
Niles K. MacDonald - San Jose CA,
Assignee:
Reflectivity, INC - Sunnyvale CA
International Classification:
C23F001/08
C23F001/12
US Classification:
216 58, 216 63, 216 64, 216 67, 216 78, 15634529, 15634533, 15634537, 252 791
Abstract:
Processes for the addition or removal of a layer or region from a workpiece material by contact with a process gas in the manufacture of a microstructure are enhanced by the use of recirculation of the process gas. Recirculation is effected by a pump that has no sliding or abrading parts that contact the process gas, nor any wet (such as oil) seals or purge gas in the pump. Improved processing can be achieved by a process chamber that contains a baffle, a perforated plate, or both, appropriately situated in the chamber to deflect the incoming process gas and distribute it over the workpiece surface. In certain embodiments, a diluent gas is added to the recirculation loop and continuously circulated therein, followed by the bleeding of the process gas (such as an etchant gas) into the recirculation loop. Also, cooling of the process gas, etching chamber and/or sample platen can aid the etching process. The method is particularly useful for adding to or removing material from a sample of microscopic dimensions.

Etching Method Used In Fabrications Of Microstructures

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US Patent:
7027200, Apr 11, 2006
Filed:
Sep 17, 2003
Appl. No.:
10/666002
Inventors:
Hongqin Shi - San Jose CA,
Gregory P. Schaadt - Santa Clara CA,
Andrew G. Huibers - Palo Alto CA,
Satyadev R. Patel - Sunnyvale CA,
Assignee:
Reflectivity, INC - Sunnyvale CA
International Classification:
G02B 26/00
US Classification:
359290, 359291, 359295, 359298
Abstract:
The present invention discloses a method and apparatus for removing the sacrificial materials in fabrications of microstructures using a vapor phase etchant recipe having a spontaneous vapor phase chemical etchant. The vapor phase etchant recipe has a mean-free-path corresponding to the minimum thickness of the sacrificial layers between the structural layers of the microstructure. This method is of particular importance in removing the sacrificial layers underneath the structural layers of the microstructure.

Method For Vapor Phase Etching Of Silicon

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US Patent:
7041224, May 9, 2006
Filed:
Mar 22, 2002
Appl. No.:
10/104109
Inventors:
Satyadev R. Patel - Elk Grove CA,
Gregory P. Schaadt - Santa Clara CA,
Douglas B. MacDonald - Los Gatos CA,
Hongqin Shi - Santa Clara CA,
Andrew G. Huibers - Mountain View CA,
Peter Heureux - Felton CA,
Assignee:
Reflectivity, Inc. - Sunnyvale CA
International Classification:
B81C 1/00
US Classification:
216 2, 216 24, 216 72, 216 73, 216 74, 216 79
Abstract:
The etching of a material in a vapor phase etchant is disclosed where a vapor phase etchant is provided to an etching chamber at a total gas pressure of 10 Torr or more, preferably 20 Torr or even 200 Torr or more. The vapor phase etchant can be gaseous acid etchant, a noble gas halide or an interhalogen. The sample/workpiece that is etched can be, for example, a semiconductor device or MEMS device, etc. The material that is etched/removed by the vapor phase etchant is preferably silicon and the vapor phase etchant is preferably provided along with one or more diluents. Another feature of the etching system includes the ability to accurately determine the end point of the etch step, such as by creating an impedance at the exit of the etching chamber (or downstream thereof) so that when the vapor phase etchant passes from the etching chamber, a gaseous product of the etching reaction is monitored, and the end point of the removal process can be determined. The vapor phase etching process can be flow through, a combination of flow through and pulse, or recirculated back to the etching chamber. A first plasma or wet chemical etch (or both) can be performed prior to the vapor phase etch.

Apparatus And Method For Detecting An Endpoint In A Vapor Phase Etch

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US Patent:
7189332, Mar 13, 2007
Filed:
Oct 11, 2002
Appl. No.:
10/269149
Inventors:
Satyadev R. Patel - Elk Grove CA,
Gregory P. Schaadt - Santa Clara CA,
Douglas B. MacDonald - Los Gatos CA,
Niles K. MacDonald - San Jose CA,
Hongqin Shi - San Jose CA,
Assignee:
Texas Instruments Incorporated - Dallas TX
International Classification:
C23F 3/12
US Classification:
216 2, 216 24, 216 60, 216 73, 216 79, 438 8, 438 16, 438706
Abstract:
Processes for the removal of a layer or region from a workpiece material by contact with a process gas in the manufacture of a microstructure are enhanced by the ability to accurately determine the endpoint of the removal step. A vapor phase etchant is used to remove a material that has been deposited on a substrate, with or without other deposited structure thereon. By creating an impedance at the exit of an etching chamber (or downstream thereof), as the vapor phase etchant passes from the etching chamber, a gaseous product of the etching reaction is monitored, and the endpoint of the removal process can be determined. The vapor phase etching process can be flow through, a combination of flow through and pulse, or recirculated back to the etching chamber.

Methods And Apparatus Of Etch Process Control In Fabrications Of Microstructures

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US Patent:
7645704, Jan 12, 2010
Filed:
Sep 17, 2003
Appl. No.:
10/666671
Inventors:
Hongqin Shi - San Jose CA,
Gregory P. Schaadt - Santa Clara CA,
Assignee:
Texas Instruments Incorporated - Dallas TX
International Classification:
H01L 21/302
US Classification:
438706, 438 9, 438714, 438723, 134 11
Abstract:
The present invention provides a method for removing sacrificial materials in fabrications of microstructures using a selected spontaneous vapor phase chemical etchants. During the etching process, an amount of the etchant is fed into an etch chamber for removing the sacrificial material. Additional amount of the etchant are fed into the etch chamber according to a detection of an amount or an amount of an etching product so as to maintaining a substantially constant etching rate of the sacrificial materials inside the etch chamber. Accordingly, an etching system is provided for removing the sacrificial materials based on the disclosed etching method.
Gregory P Schaadt from Santa Clara, CA, age ~60 Get Report