규소에 있어서 인의 확산공정에 대한 2차원적 수치해석 모델

Abstract

반도체 집적회로 제조과정중의 불순물 확산공정은 일반적으로 예비석출과 주입의 두 공정으로 이루어진다.

본 연구에서는 불활성 분위기나 질소 분위기에서 인의 예비석출과 주입을 시행할시 확산에 대한 모델을 설정함으로써 수치해석법에 의해 최종 농도분포를 계산하였다. 확산계수의 모델로서는 공공기구를 기초하여 Fair와 Tsai가 제시한 모델을 사용하였다. 고농도 인의 확산 경우에는 불순물 원자로 인한 변형때문에 생기는 에어지 갭 감소효과를 고려하였다. 인의 표면 농도는 내삽법으로 구하여 사용하였다. 확산 방정식을 선형화하기 위하여 유한 차분법을 사용하였으며, 해를 구하기 위해서는 Stone의 SIP 방법을 적용하였다.

The impurity diffusion processes in semiconductor integrated circuit fabrication in general consist of predeposition and drive-in diffusions.

In the present work, the final impurity distributions in silicon through phosphorus diffusion processes in inert or nitrogen atmosphere were calculated using computer-aided numerical analysis methods.

The diffusion coefficients of substitutional impurities were modeled with vacancy mechanism. It is assumed that the phosphorus diffusion is controlled by Fair and Tsai model. An effect of the narrowed energy gap due to the strain by very high concentration of phosphorus was approximated by the interpolation. For the linearization of diffusion equation the finite difference method was utilized. For the solution of the resulting simultaneous equations the strong implicit procedure by Stone was used.

The impurity diffusion processes in semiconductor integrated circuit fabrication in general consist of predeposition and drive-in diffusions.

In the present work, the final impurity distributions in silicon through phosphorus diffusion processes in inert or nitrogen atmosphere were calculated using computer-aided numerical analysis methods.

The diffusion coefficients of substitutional impurities were modeled with vacancy mechanism. It is assumed that the phosphorus diffusion is controlled by Fair and Tsai model. An effect of the narrowed energy gap due to the strain by very high concentration of phosphorus was approximated by the interpolation. For the linearization of diffusion equation the finite difference method was utilized. For the solution of the resulting simultaneous equations the strong implicit procedure by Stone was used.