Minority carrier lifetime in Czochralski silicon containing oxide precipitates
Photoconductance methods were used to measure minority carrier lifetime in p-type Czochralski silicon processed under very clean conditions to contain oxide precipitates. 24 different sample types were characterised by chemical etching and transmission electron microscopy to determine the density an...
| Main Authors: | , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2010
|
| Summary: | Photoconductance methods were used to measure minority carrier lifetime in p-type Czochralski silicon processed under very clean conditions to contain oxide precipitates. 24 different sample types were characterised by chemical etching and transmission electron microscopy to determine the density and morphology of the precipitates. For samples processed to contain mainly unstrained precipitates, the lifetime component associated with oxide precipitates was extremely high (up to 4.5ms at an injection level corresponding to half of the doping level). The lifetime results show that the rate of recombination depends upon the strain state of the precipitates. Recombination at unstrained oxide precipitates (sometimes referred to as "ninja particles") is weak, with a capture coefficient of approximately 1 × 10 -7 cm 3s -1. Strained oxide precipitates and defects associated with them (dislocations and stacking faults) act as much stronger recombination centres with a capture coefficient of approximately 3 × 10 -6cm 3s -1. Recombination at strained precipitates and associated defects was found to depend mainly on their density (as opposed to size). ©The Electrochemical Society. |
|---|