Bulk defect induced low-frequency noise in n+-p silicon diodes

The low-frequency 1/f-like noise of gated n(+)-p silicon diodes has been measured and analyzed in terms of trapping and detrapping of holes in defect centers located in the bulk section of the space charge region at 0.43 eV below the conduction band. Both the trap characteristics and their precise physical location are resolved from the noise measurements showing that the noise producing defect region moves closer to the metallurgical junction when forward bias is increased. The noise measurements independently confirm that thermal substrate pretreatments lower the defect density in the diodes fabricated in Czochralski (CZ) grown substrates, The defect centers are assumed to be associated with precipitated oxygen/dislocation complexes.