Method for evaluating a crystalline semiconductor substrate
US6819119B2 · kind B2 · utility
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15Claims
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Key dates
| Filing date | Jan 21, 2003 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Jun 14, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/2608
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method for evaluating a crystalline semiconductor substrate which includes a collector layer, a base layer, and an emitter layer and is used for a heterojunction bipolar transistor, a layer is provided having the same composition as the base layer. The semiconductor substrate is irradiated with excitation light and change with time in intensity of photoluminescence from the layer is measured before the intensity becomes saturated. The change with time in current gain of the heterojunction bipolar transistor produced using the semiconductor substrate is determined from the change with time in the intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.