Low Temperature Transparent ITO-based Contacts for Mid-IR Applications
Published online by Cambridge University Press: 18 July 2011
In this work, thin films of Indium Tin Oxide (ITO)-based materials were tested as potential candidates for mid-IR transparent contacts on Te-doped GaSb and Si-doped InAs semiconductor wafers. Since these contacts are devoted to be inserted in Sb-based devices which are generally MBE-grown at ∼450°C, low-temperature fabrication processes were particularly tested with a maximum temperature of annealing of 400°C. 50 nm-thick ITO films were deposited on glass, Te-doped GaSb and Si-doped InAs wafers and resistivity of 8.10−4 Ω.cm combined with ∼80% of transmittance at 2 μm and ohmic contacts with a specific resistance of 3.10−4 Ω.cm2 were obtained. Then, in order to improve these properties in the mid-IR, other ITO-based materials were tested: In doped ZnO (IZO) and Zn doped ITO (ITZO). The first results obtained on these materials show that the insertion of 10% of Zn in classical ITO structure results in a degradation of the electrical properties of the layer without a real impact on its optical transmittance near 2 μm. Concerning IZO, a large improvement of the transmittance in the whole visible-mid-IR wavelength range was observed for annealed samples at a temperature as low as 350°C. However, the electrical resistivity appears very sensible to the temperature of annealing.
- Research Article
- MRS Online Proceedings Library (OPL) , Volume 1327: Symposium G – Complex Oxide Materials for Emerging Energy Technologies , 2011 , mrss11-1327-g09-02-s08-02
- Copyright © Materials Research Society 2011