我们知道,Si中的缺陷(如位错、层错、滑移线等)和某些微量杂质(Cu、Au、Fe等),对器件性能和成品率的影响是很大的。而最坏的情况还是晶体缺陷与重金属杂质的结合(缺陷处原子排列较松散,则金属原子易于沉淀在缺陷附近),这往往是影响器件成品率的一个重要因素。因此,设法减少金属杂质在Si中的含量,对提高器件成品率(特别是对受P-N结漏电限制的成品率)将具有很重要的意义。 We know that the defects in Si (such as dislocations, stacking faults, slip lines, etc.) and some trace impurities (Cu, Au, Fe, etc.) have a great influence on device performance and yield. The worst case is the combination of crystal defects and heavy metal impurities (defects are loosely arranged, and metal atoms tend to precipitate near the defects), which is often an important factor affecting device yield. Therefore, trying to reduce the content of metal impurities in Si will be of great importance for improving the device yield, especially for the yield limited by P-N junction leakage.