Investigation of carrier transport through silicon wafers by photocurrent measurements
| Autor: | Dean G. Hafeman, Luc J. Bousse, Shahriar Mostarshed, Manuela Adami, Marco Sartore, Claudio Nicolini |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 75:4000-4008 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.356022 |
| Popis: | Measurement of the ac photocurrent in metal/insulator/semiconductor capacitors can be used as a tool to measure minority‐carrier diffusion and lifetime. The amplitude of the ac photocurrent generated at a silicon surface biased into inversion depends on the number of excess minority carriers present at that surface. By comparing this amplitude when intensity‐modulated light is directed to each side of the same device, minority‐carrier diffusion from the back to the front of the device can be characterized. An analytical model of this transport process predicts the dependence of the ac photocurrent on frequency and wafer thickness, and allows the determination of a value of the bulk lifetime free of the influence of surface recombination. Measurements under low‐light intensity levels are presented on n‐type silicon wafers with lifetimes in the 10–100 μs range. Lifetimes are found about a factor of 2 lower than those measured with noncontact photoconductive decay, at high‐light intensity levels. This is exp... |
| Databáze: | OpenAIRE |
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