p/sup +//n/sup -//n/sup +/ Cz-Si detectors processed on p-type boron doped substrates with thermal donor induced space charge sign inversion

We have processed pad detectors on high resistivity p-type Cz-Si wafers. The resistivity of the boron-doped silicon is approximately 1.8 kOmegacm after the crystal growth. The detector process was carried as common procedure for standard n-type wafers, resulting p⁺/p-/n⁺ detector structures. During the last process step, i.e. sintering of aluminum electrode, the p-type bulk was turned to n-type with generation of thermal donors (TD). This way, high oxygen concentration p⁺/n-/n⁺ Cz-Si detectors were realized with low temperature process. The full depletion voltage of detectors could be tailored between wide range from 30 V up to close 1000 V by changing heat treatment at 400degC-450degC duration from 20 to 80 minutes. The space charge sign inversion (SCSI) in the TD generated devices (from p⁺/p-/n⁺ to p⁺/n-(inverted)/n⁺) has been verified by the transient current technique (TCT) measurements. The detectors show very small increase of full depletion voltage after irradiations with 24 GeV/c protons.