Surface Structure and Properties of Ti/Au Composite Electrode on CdZnTe (111)B Surface

Abstract

Abstract: In recent years, detectors made from cadmium zinc telluride (CdZnTe) have become a research focal point, and proper contact characteristics have become a key issue for improving the performance of the detector. This paper mainly discusses the ohmic contact performance of Ti/Au composite electrode on the weak n-type CdZnTe crystal (111)B surface, preparation of Ti/Au composite electrode by two-step deposition process.Through AFM, FIB/TEM, XPS, I-V and other test methods, the interface structure, chemical composition and electrical properties of the interface between the electrode and CdZnTe were studied. The results show that the introduction of the Ti transition layer can reduce and improve the damage layer formed during the wafer polishing process, and increase the ohmic characteristics between the electrode and the crystal. Compared with the Cr/Au composite electrode on the CdZnTe (111)B surface, the Ti/Au composite electrode has a lower roughness, a smoother contact interface, and a lower thickness of the lattice mismatch layer. The Ti intermediate layer promotes the interdiffusion phenomenon of the gold/half interface, which is beneficial to increase the adhesion and reduce the Schottky barrier, and the presence of oxygen is not observed at the interface between the Ti/Au composite electrode and the CdZnTe contact.The I-V test shows that the Ti/Au composite electrode has better ohmic characteristics and lower Schottky barrier.

Key words: CdZnTe, Ti/Au, contact interface, ohmic characteristic, lattice mismatch layer, interdiffusion

CLC Number:

TL81
O646.5

TAO Siqi, ZHANG Jijun, WANG Shulei, QIN Meiqi, QIU Panhui, SONG Xiaolong. Surface Structure and Properties of Ti/Au Composite Electrode on CdZnTe (111)B Surface[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(6): 1089-1095.

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