US 7,536,915 B2
	Diaphragm vacuum measuring cell and method for the production of such measuring cell
Carsten Strietzel, Osterreich (Austria); Per Björkman, Aland (Finland); and Walter Berner, Schweiz (Switzerland)
Assigned to Inficon GmbH, Bad Ragaz (Switzerland)
Filed on Nov. 06, 2007, as Appl. No. 11/935,874.
Claims priority of application No. 1817/06 (CH), filed on Nov. 13, 2006.
Prior Publication US 2008/0110269 A1, May 15, 2008
Int. Cl. G01L 9/12 (2006.01)

U.S. Cl. 73—718  [73/714; 73/724]

23 Claims

1. Method for the production of a vacuum measuring cell with a diaphragm (2) as pressure transducer, wherein on the one side of the diaphragm (2) at a spacing a first housing plate (1) is disposed sealing in the margin region with a joining means (3), such that between them a reference vacuum chamber (7) is formed and that on the other side of the diaphragm (2) at a spacing a second housing plate (4) is disposed sealing in the margin region with a joining means (3), such that between them a measuring vacuum chamber (9) is formed, and that the second housing plate (4) includes an opening and connection means (5) communicating with the opening and the measuring vacuum chamber (9) disposed sealing with joining means (3) for the connection of the measuring vacuum chamber (9) with the medium to be measured, wherein the diaphragm (2) and the housing plates (1, 4) are comprised of a metal oxide, characterized in that the measuring cell is coated in a vacuum chamber (64) using an ALD method and the material deposition takes place through the opening of the measuring cell and the connection means (5) such that the inner wall of the measuring vacuum chamber (9) and the opening with the connection means (5) are covered with a protective layer (13) such that at least the joining means (3) for the diaphragm (2) is protectively covered, at least one diaphragm measuring cell (8) being placed as a substrate (63) in the vacuum chamber (64) on a substrate holder (62) which includes a heating arrangement, and subsequently the vacuum chamber (64) is evacuated with a pump system (52, 53, 54) and that, after the evacuation is completed to a desired pressure, the coating process takes place in that at least two precursor gases (57, 58) are sequentially introduced into the vacuum chamber (64) at predetermined time intervals wherein between each of these steps the chamber is purged with an inert purge gas (65) for a predetermined time and that this cycle is repeated several times such that from individual chemically reacted atomic coats a metal oxide layer (13) with desired total thickness is deposited.