Abstract:The effect of nitrogen on thermal warpage in nitrogen-doped Czochralski (CZ) silicon wafers after heat treatment was studied. After preannealing at 1000℃for 6h, the warpage of the silicon wafers was suppressed during subsequent thermal warping test due to the formation of nitrogen-oxygen clusters with smaller size. After preannealing at 1 000℃for 16 h, the silicon wafers show a large increase during thermal warping test due to the large amount of oxygen precipitation. The results indicate that the nitrogen is very effective to increasing the mechanical strength of silicon wafers of CZ silicon at high temperature.

Key words: nitrogen　thermal warpage　mechanical strength　silicon wafers