Macronix International Co., Ltd.

Yaw-Lin Hwang

Wei-Wen Chen

Yun-Chi Yang

A method for determining near-surface doping concentration is provided by utilizing surface photovoltage. A monochromatic light pulse is applied to a semiconductor substrate. When the energy of the incident light is larger than the energy gap of the semiconductor substrate, the light is absorbed by the substrate and thereby generates enough charge carriers. The carriers diffuse to the surface of the substrate and result in lowering the surface barrier, and hence, cause a shift of the surface voltage. The difference of the surface voltages, before and after the light pulse applied, is measured by using a surface photovoltage probe. Then, the doping concentration near the surface of the substrate can be determined according to the difference of the surface voltage.

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Taipei, Taiwan

Yaw-Lin Hwang