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Pyrolytic Boron Nitride (PBN) Heater with Electrostatic Hold Down Device

IP.com Disclosure Number: IPCOM000110737D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 71K

Publishing Venue

IBM

Related People

Sandstrom, RL: AUTHOR

Abstract

Disclosed is an insulated, dense, and chemically stable pyrolytic boron nitride (PBN) substrate with embedded pyrolytic graphite patterns for electrical conduction with an interdigitated electrostatic hold down (ESHD) wafer chuck pattern for holding wafers in position without screws or spring holders while depositing thin film materials at elevated temperatures in excess of 650~C. The heater is highly stable and capable of operation in high purity environments under inert atmosphere or vacuum at temperatures in excess of 1600~C. The heater would have a somewhat more limited range (around 650~C) in oxidizing environments.

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Pyrolytic Boron Nitride (PBN) Heater with Electrostatic Hold Down Device

      Disclosed is an insulated, dense, and chemically stable
pyrolytic boron nitride (PBN) substrate with embedded pyrolytic
graphite patterns for electrical conduction with an interdigitated
electrostatic hold down (ESHD) wafer chuck pattern for holding wafers
in position without screws or spring holders while depositing thin
film materials at elevated temperatures in excess of 650~C.  The
heater is highly stable and capable of operation in high purity
environments under inert atmosphere or vacuum at temperatures in
excess of 1600~C.  The heater would have a somewhat more limited
range (around 650~C) in oxidizing environments.

      This PBN heater substrate has Z75mm thick pyrolytic graphite
pattern for resistive heating with a compatible conformal boron
nitride (PBN) thick film coating, Z100mm thick.  The ESHD wafer chuck
coating consists of a graphite coating (Z75mm thick), on an
interdigitated pattern with alternating positive and negative voltage
fingers.  This top coating is sealed with the same PBN coating,
(Z25mm thick), this completes the structure.  A wafer for processing
is held in position on top of this structure.  This compact design
can be fabricated with a total thickness of <.060".

      Thermal expansion differences between the PBN, pyrolytic
graphite, and the metal coating do not cause enough strain to result
in delamination or flaking-off of any of the material...