Coating apparatus – Gas or vapor deposition – Work support
Reexamination Certificate
2001-01-08
2003-05-27
Mills, Gregory (Department: 1763)
Coating apparatus
Gas or vapor deposition
Work support
C156S345550
Reexamination Certificate
active
06569250
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and apparatus for forming silicon carbide layers on wafers and other substrates and, more particularly, to such methods and apparatus providing rotation of the wafer or other substrate.
BACKGROUND OF THE INVENTION
Silicon carbide (SiC) is increasingly recognized as an effective semiconductor material for electronic devices. SiC possesses a number of properties that make it particularly attractive for applications requiring devices to operate at high temperature, power and/or frequency. SiC exhibits highly efficient heat transfer and is capable of withstanding high electric fields.
It has been demonstrated that hot-wall chemical vapor deposition (CVD) reactors can provide epitaxial layers of SiC with morphology and doping superior to cold-wall systems. See, for example, U.S. Pat. No. 5,695,567 to Kordina et al., the disclosure of which is hereby incorporated herein by reference. It has further been demonstrated that the addition of substrate rotation to a hot-wall CVD system may improve both the per cycle capacity of the system and the uniformity of the epitaxial layers obtained. U.S. Pat. No. 4,860,687 to Frijlink discloses a device comprising a flat susceptor rotating parallel to a reference surface. The device disclosed therein may be used in a vapor phase epitaxy system.
SUMMARY OF THE INVENTION
According to preferred embodiments of the present invention, a gas driven rotation apparatus includes a base member and a platter. The base member includes an upper surface and a mounting portion formed in the upper surface. The mounting portion includes an inner recess and an annular outer channel surrounding and spaced apart from the inner recess. A plurality of drive channels extend generally radially outwardly from the inner recess to the outer channel. The drive channels are substantially straight. A drive gas entrance passage extends through the base member and has an entrance opening in the inner recess. A drive gas exhaust passage extends through the base member and has an exhaust opening in the outer channel. The platter overlies the mounting portion. The drive channels are arranged and configured such that, when a drive gas flows through the drive channels, the drive gas causes the platter to rotate relative to the base member about an axis of rotation.
Preferably, each of the drive channels defines a drive channel axis which is offset from the axis of rotation. The apparatus may include: a supplemental recess spaced apart from and disposed on a side of the inner recess opposite the outer channel; a landing located between the inner recess and the supplemental recess; and a second drive gas exhaust opening in the supplemental recess.
According to preferred embodiments of the present invention, a gas-driven rotation apparatus includes a base member and a platter. The base member includes a mounting portion having at least one generally radially extending drive channel. The at least one drive channel is substantially straight. A platter is disposed adjacent the mounting portion. The at least one drive channel is arranged and configured such that, when a drive gas flows through the at least one drive channel, the drive gas causes the platter to rotate relative to the base member about an axis of rotation.
Preferably, the at least one drive channel includes a plurality of generally radially extending drive channels formed in the mounting portion and each of the drive channels is substantially straight. Preferably, each of the drive channels defines a drive channel axis which is offset from the axis of rotation.
According to further preferred embodiments of the present invention, a gas driven rotation apparatus includes a base member and a platter. The base member includes a mounting portion having a first recess and a second recess spaced apart from the first recess. At least one drive channel extends generally radially from the first recess to the second recess. A drive gas entrance passage extends through the base member and has an entrance opening in the first recess. A drive gas exhaust passage extends through the base member and has an exhaust opening in the second recess. The platter is disposed adjacent the mounting portion. The at least one drive channel is arranged and configured such that, when a drive gas flows through the at least one drive channel, the drive gas causes the platter to rotate relative to the base member about an axis of rotation.
The apparatus may further include a drive gas supply device operative to provide a flow of drive gas through the drive gas entrance passage. The drive gas may include a noble gas. The apparatus may include a supplemental recess spaced apart from and disposed on a side of the first recess opposite the outer channel; a landing located between the first recess and the supplemental recess; and a second drive gas exhaust opening in the supplemental recess.
According to preferred method embodiments of the present invention, a method for forming a silicon carbide layer on a substrate includes providing a susceptor assembly. The susceptor assembly includes a base member and a platter. The base member includes a mounting portion having a first recess and a second recess spaced apart from the first recess. At least one drive channel extends generally radially from the first recess to the second recess. A drive gas entrance passage extends through the base member and has an entrance opening in the first recess. A drive gas exhaust passage extends through the base member and has an exhaust opening in the second recess. The platter is disposed adjacent the mounting portion. The substrate is placed on the platter. A reactant gas flow is directed across the substrate on the platter. A drive gas is directed into the gas entrance passage, through the entrance opening, through the at least one drive channel, into the exhaust opening, and through the drive gas exhaust passage whereby the drive gas causes the platter to rotate relative to the base member about an axis of rotation.
The method may include levitating the platter over the mounting portion using the drive gas. The exhaust passage may maintain the drive gas separate from the reactant gas flow. Preferably, the drive gas is argon gas.
Objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the Figures and the detailed description of the preferred embodiments which follow, such description being merely illustrative of the present invention.
REFERENCES:
patent: 3424628 (1969-01-01), Winings
patent: 4722911 (1988-02-01), Frijlink
patent: 4748135 (1988-05-01), Frijlink
patent: 4860687 (1989-08-01), Frijlink
patent: 4961399 (1990-10-01), Frijlink
patent: 4976217 (1990-12-01), Frijlink
patent: 5027746 (1991-07-01), Frijlink
patent: 5056555 (1991-10-01), Frijlink
patent: 5108540 (1992-04-01), Frijlink
patent: 5226383 (1993-07-01), Bhat
patent: 5468299 (1995-11-01), Tsai
patent: 5558721 (1996-09-01), Kohmura et al.
patent: 5674320 (1997-10-01), Kordina et al.
patent: 5695567 (1997-12-01), Kordina et al.
patent: 5704985 (1998-01-01), Kordina et al.
patent: 5759263 (1998-06-01), Nordell et al.
patent: 5788777 (1998-08-01), Burk, Jr.
patent: 5792257 (1998-08-01), Kordina et al.
patent: 5858102 (1999-01-01), Tsai
patent: 5879462 (1999-03-01), Kordina et al.
patent: 6005226 (1999-12-01), Aschner et al.
patent: 6030661 (2000-02-01), Kordina et al.
patent: 6039812 (2000-03-01), Ellison et al.
patent: 6048398 (2000-04-01), Vehanen et al.
patent: 6093253 (2000-07-01), Löfgren et al.
patent: 2001/0002948 (2001-06-01), Aschner et al.
Declaration of Michael Paisley under 37 C.F.R. § 1.132, dated Nov. 6, 2002.
Press Release,Sterling Semiconductor Placed Order for Second Epigress SiC CVD System,Oct. 24, 2001, at http://www.compoundsemiconductor.net/PressReleases/2001/PR10240102.htm.
Kordina Olle
Paisley Michael
Sumakeris Joseph John
Cree Inc.
Mills Gregory
Moore Karla
Myers Bigel & Sibley & Sajovec
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