Optimum Oxygen Content of Wafers
Original Publication Date: 1978-Aug-01
Included in the Prior Art Database: 2005-Feb-21
Molten silicon dissolves portions of the quartz crucible during crystal pulling operations. As a consequence, Czochralski-grown silicon materials contain dissolved (interstitial) oxygen. Because the oxygen segregation coefficient is greater than 1, the oxygen concentration is typically largest at the first part of the crystal (seed) and decreases toward the end (tail) of the boule. This seed-tail oxygen concentration variation ranges between the oxygen solid solubility limit of Approximately 50 ppm down to 8 ppm, respectively.