Positioning stage for cryogenic chip probing.

Abstract

The invention concerns a wafer positioning stage with 4 degrees of freedom for use in a cryogenic environment and suited for cryogenic chip probing. 10 Special focus has been attended to realize high speed and considerable lifetime improvements with respect to current piezo based positioners. In the presented concept we introduce cryogenic compatible electromagnetic linear motors in close 15 distance to the contacting probes which enables high speed, no wear and precise displacements. All required 4 degrees of freedom, positioning in X, Y, rotation around Z and probing action Z displacement have been integrated in a stand-alone module. 20 Special attention has been put to keep the substrate table at the desired temperature under moving circumstances and minimizing the dissipation during cryogenic chip probing.