[21p-224B-1~8] 2.2 Detection systems

[21p-224B-5] Development of X-ray Imaging Sensors Based on Epitaxially Grown Thick CdTe Layers on Si Substrates

〇Madan Niraula¹, Kazuhito Yasuda¹, Shintaro Tsubota¹, Taiki Yamaguchi¹, Junya Ozawa¹, Takuro Mori¹, Yasunori Agata¹ (1.NIT)

Keywords:X-ray imaging detector, CdTe, epitaxial growth

Fine-pixels X-ray imaging sensor was developed using epitaxially grown CdTe layer on Si substrate. The sensor has an effective area of 12 x 12 mm², which was developed by using a 60 mm- thick single crystal CdTe epilayer grown on 25.4 x 25.4 mm² sized n⁺-Si substrate. The sensor consists of (128x128) pixels in a 80 mm pitch in a p-CdTe/n-CdTe/n+-Si heterojunction diode structure. Each pixel in the array is bump-bonded to CMOS read-out ASIC. The sensor is operated in the charge integration mode. The basic performance of this sensor was evaluated by measuring the array dark currents and taking the X-ray images. Details on the array fabrication, characterization along with a review of our epitaxial growth based detector development technique will be presented.