Microdefects Of Boron-doped Single Crystal Silicon And Its Rapid Thermal Process Behavior Research

In this paper,the micro-defects in boron-doped single crystal silicon were systematically studied by using Rapid Thermal Processing?RTP?technology and low-high conventional heat treatment process.The formation of bulk microdefects?BMD?and near-surface active area denuded zone?DZ?of light-doped boron and heavy-doped boron Czochralski?CZ?silicon after single-or two-step RTP and subsequent low-high heat treatment in Ar and O₂ atmosphere was investigated.At the same time,the rapid thermal processing?RTP?of boron-doped single crystal silicon with primary micro defects on the surface was studied.The regulation of RTP technology on micro-defects in single crystal silicon and the promotion of near-surface denuded zone?DZ?were further analyzed.The effects of RTP annealing atmosphere,annealing time and cooling rate on the formation of BMD and DZ in boron-doped single crystal silicon were investigated by single-step RTP and low-high heat treatment in Ar atmosphere and O₂ atmosphere.In Ar atmosphere,it was found that BMD density and DZ width of light boron-doped Czochralski silicon increased with the increase of RTP time,BMD density increased and DZ width decreased with the increase of RTP cooling rate.Nevertheless,for heavy boron doped Czochralski silicon,with the increase of RTP time,BMD density increased,and no DZ appeared.With the increase of RTP cooling rate,BMD density decreased,but no DZ also appeared.In the O₂ atmosphere,it is found that with the extension of RTP time,the BMD density decreases and the DZ width increases in lightly doped and heavily doped boron Czochralski silicon.As the RTP cooling rate increases,the BMD density increases and the DZ width decreases in both lightly doped and heavily doped boron Czochralski silicon.However,the low density of single crystal silicon BMD during heat treatment in an O₂ atmosphere is not conducive to internal gettering during later device fabrication.Two-step RTP and subsequent low-high heat treatment of boron-doped single crystal silicon in?Ar/O₂?or?O₂/Ar?atmosphere were studied.It was found that the BMD density and the near-surface DZ width of the single crystal silicon changed correspondingly with the change of RTP time and cooling rate.By changing RTP time and cooling rate,BMD in single crystal silicon can be reasonably distributed,and a wide DZ can be formed near the surface to meet the requirement of impurity absorption in subsequent device manufacturing process.