Progress in another detector research

[ Instrument Network Instrument R & D ] The core electronic components are the core of electronic information systems. In the past ten years, with the support of major national science and technology projects, China has made a series of major breakthroughs and achievements in the above fields. Zoom out. In particular, it has played an important role in meeting national strategic needs and supporting the sustainable development of key industries.

The silicon drift detector (SDD) structure was proposed by E.Gatti and P.Rehak in 1983. Because its output capacitance is small (generally less than 0.1pF) and does not depend on the area of ​​the detector, the electrical noise is generally much smaller than the same area and thickness The Si-PIN detector can achieve or even exceed the energy resolution of a Si (Li) detector that requires liquid nitrogen cooling using only simple semiconductor refrigeration, making the detector suitable for material composition analysis, medical imaging, Astrophysics, nuclear physics, and nuclear technology have a wide range of applications. China is also committed to the development of SDD core components.

In order to accelerate the localization of SDD devices, the research team of Jia Rui from the Institute of Microelectronics has carried out core technology research on SDD detection chips. By using heterojunction and its planar process to prepare SDD, the dark state leakage current (nA level has been greatly reduced. ), Which reduces the manufacturing cost and improves the reliability of the device. In the end, the team successfully developed silicon drift detectors with an area of ​​20 mm2, 79 mm2, and 314 mm2, which can clearly detect X-rays with an energy of 5.9 keV emitted by 55Fe. At the same time, it can detect radiation emitted by radiation sources such as 241Am. Alpha particles and X-rays. The team has formed core competitiveness in device design, working mechanism and process preparation of silicon heterojunction drift detectors, and has completely independent intellectual property rights.

The silicon drift detector has high detection efficiency and high energy resolution for 1 ~ 10keV soft X-rays. Applying it to weak X-ray detection in X-ray pulsar navigation can reduce the detector area and improve the signal-to-noise ratio . It is one of the detectors with high energy resolution in the field of high-energy particle detection. It is mainly used to detect high-energy particles and X-rays. It has the advantages of high sensitivity, high energy resolution, and high counting rate. It is used in key areas such as astronomical observation, medical and security Has important applications. Because traditional SDD device preparation requires complete reliance on microelectronic processes and equipment, it is difficult and costly. The technology and market of this device and its high-end detection equipment have been monopolized by developed countries for a long time, and only devices with an area of ​​100 mm2 or less can be prepared. .