A Study on Lateral Surface Treatment of the CdTe X-ray image-sensor

摘要

A CdTe X-ray sensor for dental X-ray imaging is fabricated and the effect of a lateral surface treatment is investigated. Due to non-uniform edge pixels in the CdTe X-ray sensor, the number of effective pixels that can be used for the final image is reduced, and a line defect is introduced when several sensors are put together for the target resolution. To improve the roughness of the lateral surface, a lateral surface polishing process is introduced. The polishing process reduces dead pixels by 76%, from 304 to 76. By lateral surface polishing, most of the dead pixels near the device edge become normal pixels. The non-uniform edge pixels are improved by the lateral surface treatment without affecting the central pixels of the CdTe X-ray image sensor. The effective resolution is extended to the edges of device; therefore, the entire area of the CdTe X-ray sensor can be used for the final image.