{"title":"X-Ray Detector With Internal Gain Based on a SiC npn Structure","authors":"Jing Wang;Liang Chen;Song Bai;Leidang Zhou;Fangbao Wang;Silong Zhang;Tingting Fan;Runhua Huang;Shaohua Yang;Geng Tian;Xiaoping Ouyang","doi":"10.1109/LED.2024.3451623","DOIUrl":null,"url":null,"abstract":"A two-terminal npn device based on 4H-SiC has been employed as a radiation detector for the first time. This device was designed as a vertical npn structure with a sensitive area of up to 1 cm2, and the thickness of the sensitive layer was about \n<inline-formula> <tex-math>$30~\\mu $ </tex-math></inline-formula>\nm. The detector exhibited a low dark current of \n<inline-formula> <tex-math>$\\sim ~0.12$ </tex-math></inline-formula>\n nA\n<inline-formula> <tex-math>$\\cdot $ </tex-math></inline-formula>\ncm\n<inline-formula> <tex-math>$^{-{2}}$ </tex-math></inline-formula>\n with a fully depleted sensitive region at 200 V. The sensitivity of unit area of the detector achieved \n<inline-formula> <tex-math>$36.67~\\mu $ </tex-math></inline-formula>\nC\n<inline-formula> <tex-math>$\\cdot $ </tex-math></inline-formula>\nGy\n<inline-formula> <tex-math>$^{-{1}} \\cdot $ </tex-math></inline-formula>\ncm\n<inline-formula> <tex-math>$^{-{2}}$ </tex-math></inline-formula>\n (\n<inline-formula> <tex-math>$28.09~\\mu $ </tex-math></inline-formula>\nA @ 0.766 Gy/s) to X-ray illumination (generated by bremsstrahlung with a tungsten target with tube voltage 30 kV) at 200 V, which was attributed to the amplification mechanism of the npn structure. Compared with the response characteristics of a SiC-PiN detector with the same sensitive volume, the gain of the two-terminal SiC npn detector was estimated to be 11.46 at 200 V. Specifically, the internal gain of the detector increased with the X-ray dose rate, where the X-ray photocurrent worked as the base current in the BJT devices. The internal gain also increased with the bias voltage due to the Early effect. Moreover, the two-terminal SiC npn detectors had a good switching response to X-rays and showed great potential in the applications of radiation detection.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 11","pages":"2142-2145"},"PeriodicalIF":4.1000,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Electron Device Letters","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10659085/","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
A two-terminal npn device based on 4H-SiC has been employed as a radiation detector for the first time. This device was designed as a vertical npn structure with a sensitive area of up to 1 cm2, and the thickness of the sensitive layer was about
$30~\mu $
m. The detector exhibited a low dark current of
$\sim ~0.12$
nA
$\cdot $
cm
$^{-{2}}$
with a fully depleted sensitive region at 200 V. The sensitivity of unit area of the detector achieved
$36.67~\mu $
C
$\cdot $
Gy
$^{-{1}} \cdot $
cm
$^{-{2}}$
(
$28.09~\mu $
A @ 0.766 Gy/s) to X-ray illumination (generated by bremsstrahlung with a tungsten target with tube voltage 30 kV) at 200 V, which was attributed to the amplification mechanism of the npn structure. Compared with the response characteristics of a SiC-PiN detector with the same sensitive volume, the gain of the two-terminal SiC npn detector was estimated to be 11.46 at 200 V. Specifically, the internal gain of the detector increased with the X-ray dose rate, where the X-ray photocurrent worked as the base current in the BJT devices. The internal gain also increased with the bias voltage due to the Early effect. Moreover, the two-terminal SiC npn detectors had a good switching response to X-rays and showed great potential in the applications of radiation detection.
期刊介绍:
IEEE Electron Device Letters publishes original and significant contributions relating to the theory, modeling, design, performance and reliability of electron and ion integrated circuit devices and interconnects, involving insulators, metals, organic materials, micro-plasmas, semiconductors, quantum-effect structures, vacuum devices, and emerging materials with applications in bioelectronics, biomedical electronics, computation, communications, displays, microelectromechanics, imaging, micro-actuators, nanoelectronics, optoelectronics, photovoltaics, power ICs and micro-sensors.