Title :
Electrical properties of the stacked ZnS/photo-enhanced native oxide passivation for long wavelength HgCdTe photodiodes
Author :
Lin, C.T. ; Su, Y.K. ; Huang, H.T. ; Chang, S.J. ; Chen, G.S. ; Sun, T.P. ; Luo, J.J.
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
5/1/1996 12:00:00 AM
Abstract :
A new surface treatment method, i.e., stacked ZnS/photo-enhanced native oxide, is proposed for HgCdTe passivation. The photo native oxide layer was deposited by direct photo chemical vapor deposition (DPCVD) using a deuterium (D/sub 2/) lamp as the optical source. By using this method, we found that there is no accumulation of Hg in the oxide/HgCdTe interface regions. Since the photo chemical vapor native oxidation is a dry oxidation method deposited at a low temperature, it can effectively suppress the Hg enhancement and the Cd depletion effects and thus obtain a high quality interface. The electrical properties of a Au-ZnS/photo-enhanced native oxide/HgCdTe metal-insulator-semiconductor (MIS) diodes were characterized by capacitance-voltage (C-V) measurement. It was found that the flat band voltage of such a MIS diode is close to 0.2 V with an effective fixed oxide charge lower than 1/spl times/10/sup 10/ cm/sup -2/.
Keywords :
II-VI semiconductors; MIS devices; cadmium compounds; chemical vapour deposition; mercury compounds; oxidation; passivation; photochemistry; photodiodes; surface treatment; Au-ZnS-HgCdTe; Au-ZnS/photo-enhanced native oxide/HgCdTe metal-insulator-semiconductor diodes; Cd depletion effects; D/sub 2/; D/sub 2/ lamp; Hg enhancement; HgCdTe; HgCdTe passivation; capacitance-voltage measurement; direct photo chemical vapor deposition; dry oxidation method; effective fixed oxide charge; electrical properties; long wavelength HgCdTe photodiodes; optical source; oxide/HgCdTe interface regions; photo chemical vapor native oxidation; photo native oxide layer; stacked ZnS/photo-enhanced native oxide passivation; surface treatment method; Capacitance-voltage characteristics; Chemical vapor deposition; Diodes; Mercury (metals); Optical surface waves; Oxidation; Passivation; Photodiodes; Surface treatment; Zinc compounds;
Journal_Title :
Photonics Technology Letters, IEEE
