Epi test (ET) wafers are test wafers that can be, or have been utilized for testing and developing epitaxial deposition processes. The front side is mirror polished, and passes our class 100 bright light inspection process. ET wafers may have epitaxial silicon on the front surface. Epi means “like” in Greek and is indistinguishable from the virgin test wafer surface since the epi has the exact same crystal structure.
They are sold in 3 orientation categories including: mixed; <100>; and <111>.
Mixed ET wafers can be any type, any orientation, any resistivity, any thickness, any flats, and any back surface. Any back surface means the back surface can be lapped, or etched, or polished, or with oxide.
<100> ET wafers can be any type, any resistivity, any thickness, with any back surface. They are sorted by flats into 2 categories so that the customer will receive <100> wafers with 90 degree flats (originally P<100> material) or 180 degree flats (originally N<100> material) depending upon customer preference.
<111> ET wafers can be any type, any resistivity, any thickness, with any back surface. They are sorted by flats into 2 categories so that the customer will receive <111> wafers with 1 major flat (originally P<111> material) or 45 degree flats (originally N<111> material) depending upon customer preference.
See inventory purchase list for availability.