What Is the Function of Bubbles in Quartz Crucible

The bubbles in quartz crucibles are both necessary and harmful for the growth of Czochralski monocrystalline silicon. In the outer layer of the crucible, there are a large number of bubbles, most of which are formed during the preparation of the crucible. These bubbles are necessary to maintain mechanical stability. However, in the non-bubble inner layer, bubbles can cause gases and impurities to be released from the crucible into the melt, thereby disturbing the growth of the monocrystal.

Therefore, as the micro-bubbles in the transparent layer continually grow, the bubbles near the inner surface rupture, releasing impurities in the form of microparticles and micro-bubbles towards the silicon crystal growth interface. This directly affects silicon crystallization (crystallization rate, whole rod rate, heating time, direct processing cost, etc.) and the quality of the single crystal ingot (such as black chips and perforated wafers). At the same time, the formation of cristobalite on the inner wall may lead to particles dissolving and eroding into the silicon melt. When these particles combine with the growing crystal, they can cause the formation of dislocations (i.e., structural loss), thereby reducing crystal yield.