硅外延片中的杂质控制

Control of Impurities in Epitaxial Wafers of Silicon

有5类掺杂源影响硅的外延片中的杂质分布。主掺杂质控制外延层的杂质浓度,决定外延层的电阻率。固态外扩散、气相自掺杂和系统自掺杂影响衬底界面附近的外延层杂质浓度的深度分布。该文介绍了此3类掺杂源的掺杂过程和抑制方法。金属杂质在外延层中对器件有害,防止沾污和使用吸杂技术能降低金属杂质在外延层中的浓度。

There are five different doping sources which can influence the distribution of impurities in silicon epitaxial wafers.The major dopant determines the concentration of impurities in the epitaxial layer and the resistivity of the layer.The outward difusion in solid state,self doping in gaseous phase and self doping of the system can influence the impurities distribution in the area close to the boundary layer of the substrate across the depth.This paper introduces the doping processes and the suppressing methods of three different doping sources.Metallic impurities in the epitaxial layer can be harmful to the devices,but prevention of contamination and adoption of gettering technique can lower the concentration of impurities in the epitaxial layer. 