High-Speed and Responsivity 4H-SiC 8 x 8 p-i-n Ultraviolet Photodiode Arrays With Micro-Hole Structure

In this brief, high-performance 8 x 8 arrays of 4H-SiC p-i-n ultraviolet (UV) photodiodes (PDs) with micro-hole structure are demonstrated. In order to improve the performance of the device, a periodic micro-hole structure (diameter = 4 mu m) was etched from the cap layer (p(+) layer) to the i layer, which will elevate the effective absorption of UV light. The pixels in 4H-SiC p-i-n array show a low dark current of less than 2 x 10(-14) A and a high yield of 98.4%. Devices with 4-mu m micro-hole reach a peak spectral responsivity of 0.159 A/W at 280 nm, which is 23.3% higher than that of the device without micro-hole. Moreover, the device has a faster response time of 2.2 ns and a high UV/visible rejection ratio of more than 10(4). The progress on the response performance is significant to the development of UV detection imaging.