Reduction of Oxygen Precipitation
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Oxygen precipitation in silicon wafers with an oxygen concentration above 30 ppm and with an initial high temperature heat treatment at 1150ŒC for 30 min. in O2 and HCl can be reduced considerably during device processing. A heat treatment at about 900ŒC is implemented for 30 min. after any process step performed between 550 and 700ŒC, which can produce an embryonic population of nucleation sites for oxygen precipitation. The 900ŒC heat treatment destroys the embryonic nucleation sites in silicon without altering the device parameters significantly. Therefore, subsequent processing with temperatures about 750ŒC does not lead to any formation of oxygen precipitation nucleation sites because of the absence of the embryonic nucleation sites.