Based on silicon planar processing technology,the study of PIPS detector was carried out.The n-type silicon wafers,which were 4 inches in diameter and 300μm thickness and N〈111〉crystal orientation were used in a detector fabrication.Detectors were taped out with different active areas such as 10 mm×10 mm andφ20 mm and so on.The dark current of the detector Based on silicon planar processing technology, the study of PIPS detector was carried out. The n-type silicon wafers, which were 4 inches in diameter and 300 μm thickness and N <111> crystal orientation were used in a detector fabrication. Dectectors were taped out with different active areas such as 10 mm × 10 mm and φ20 mm and so on. dark current of the detector