公开(公告)号：US3874920A

公开(公告)日：1975-04-01

申请号：US37442673

申请日：1973-06-28

Applicant: IBM

Inventor： CHAPPELOW RONALD E ,  DOULIN JR JOSEPH ,  LIN PAUL T ,  SARKARY HOMI G

IPC: H01L29/78 ,  H01L21/28 ,  H01L21/314 ,  H01L21/321 ,  B44D1/14

CPC classification number: H01L21/32105 ,  Y10S438/934

Abstract: A method for the in-situ boron doping of polycrystalline silicon is disclosed wherein the boron-to-silicon ratio is increased beyond the limit of solubility of boron in silicon. Using appropriate flow rates of SiH4, B2H6, and H2, and deposition temperature, boron rich silicon is deposited upon a substrate. The boron is in solution in the silicon to the limit of its solubility and is present in excess amounts in boron-rich phases believed to be boron silicides. The deposited boron-rich polycrystalline silicon is subjected to a thermal oxidation step during which the dissolved boron is depleted into the growing oxide while the boron-rich phases decompose allowing the freed boron to go into solution in the silicon to replace the boron which is lost to the thermal oxide. By proper selection of parameter values, based upon experimentally determined silicon resistivity-to-B2H6 flow rate-to-thermal oxidation relationships, the boron-rich phases are substantially eliminated from the polycrystalline silicon at the same time that the thermal oxidation step is completed thereby yielding minimum resistivity doped silicon in the final structure.

Abstract translation: 公开了一种用于多晶硅的原位硼掺杂的方法，其中硼与硅的比例增加超过硼在硅中的溶解度的限度。 使用适当的SiH 4，B 2 H 6和H 2的流速和沉积温度，富硼富集沉积在基底上。 硼在硅中的溶液中至其溶解度的极限，并且在被认为是硅化硼的富硼相中以超过量存在。 沉积的富含硼的多晶硅经受热氧化步骤，在此期间，溶解的硼被耗尽到生长的氧化物中，而富含硼的相分解，允许释放的硼进入硅中的溶液中以替代丢失的硼 到热氧化物。 通过适当选择参数值，基于实验确定的硅电阻率 - B2H6流速 - 热氧化关系，在完成热氧化步骤的同时基本上从多晶硅中除去富含硼的相 在最终结构中产生最小电阻率掺杂硅。