Provided is a test wafer and a process for making the same that includes a plurality of peaks on a surface thereof that have a cross-section sufficient to reduce the stress of a refractory metal layer deposited thereon. The present invention is based upon the discovery that by fracturing a refractory metal layer on a test wafer reduces the stress to which the test wafer is subjected. The test includes a substrate having a surface with a plurality of peaks and troughs formed therein defining a roughness. Typically, the roughness Ra is in the range of 500 to 1200 micrometers.
An improved component for use in a deposition chamber is constructed from ceramic zirconia and a stabilizing compound. The zirconia is preferably in a partially stabilized form and is coated with a metallic layer such as thermally sprayed aluminum. The surface of the zirconia is roughened to improve adhesion between the zirconia and the aluminum. Alternatively, an intermediate layer may be deposed between the zirconia and the metallic layer to improve the bonding between the layers. The coated zirconia component resists flaking when covered with materials that are being deposited in the deposition chamber and, thus, reduces the likelihood that devices being constructed in the deposition chamber will be contaminated by loose particles.
