应用光伏方法估算硅单晶表面态俘获截面

Estimation for the Capture Cross Sections of Surface-State of Silicon Single Crystal by Photovoltaic Method

提出一个可以非破坏性地估算半导体单晶的表面态俘获截面σon和σ-p 的新方法 .此法基于变温光伏测量 ,采用 (111) p型硅单晶 (NA =1.5× 10 16cm-3 )为实验样品 .由于表面势垒高度ΦBP =0 .5 75 6 V,表面复合速度 sn =4 .8× 10 3 cm . s-1以及表面态密度 Ds=6 .7× 10 11cm -2 . e V-1可由光伏方法测算 ,则表面态俘获截面σon ≈ 5× 10 -13 cm2 与σ-p ≈ 2× 10 -12 cm2 可通过应用Shockley- Read体复合理论于表面而被估算 .

A new method which can nondestructively measure, then estimate the capture cross sections of surface state σ o n and σ - p (or σ n + and σ p 0) of silicon single crystal is proposed. This method is based on the photovoltage measurements at various temperatures. The photovoltage experiment was carried out with a (111) p Si single crystal ( N A =1.5×10 16 cm -3 ). Owing to that the surface barrier height Φ BP =0.575 6 V, the surface recombination velocity S n =4.8×10 3 cm·s -1 and the surface state density D s =6.7×10 11 cm -2 ·eV -1 of the sample can be determined by photovoltaic method, the capture cross sections of surface state σ o n ≈5×10 -13 cm 2 and σ - p ≈2×10 -12 cm 2 can also be estimate by applying Shockley Read bulk recombination theory for surface. This result is consistent with related results obtained by other method.