Fabrication of Pbx+Sn1-xTe thin films using vapor deposition

• Main Authors: Lim, Jose Renato G., Mancilla, Delfin A.
• Format: text
• Language: English
• Published: Animo Repository 1996
• Subjects: Thin films; Semiconductors; Vapor-plating; Physics
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/4156
• Institution: De La Salle University

PbxSn1-xTe thin films were fabricated using vertical vapor deposition technique. The pre-reacted PbxSn1-xTe crystals with varying concentrations at x = 0.2, 0.5, and 0.8 were placed on a quartz tube, heated at 850 centigrade and was deposited on a glass substrate at a temperature of = 318 centigrade. The quartz ampoule with an inner diameter of 0.9 cm and length of 25 cm closed on one end was attached to a fabricated high vacuum system with a vacuum pressure of 10 Torr oriented in the vertical direction. Improvised stainless clips hold the glass substrate which was oriented in the vertical direction while the source material was heated at 850 centigrade using a temperature controlled single zone furnace. XRD analysis of the thin films at x = 0.2 show that sharp diffraction peaks due to [1,1,1], [2,0,0], [2,2,0], [3,1,1], [2,2,2], [4,0,0], [4,2,0], [4,2,2] planes were characteristic of the face centered cubic (rocksalt) structure of PbSnTe and the lattice parameter of the crystal was found to be 6.64 nm. Part of the study was also focused on observing the surface quality of the thin film sample (both external and micrograph features), the diameter of the quartz glass tube used, its deposition time, the amount of mass of the pre-reacted crystal that will be deposited on the glass substrate, and the temperature of the glass substrate. From the results of the experiment, it was found out that the optimal deposition time was 30 minutes. Two samples at x = 0.2 were deposited using two different diameters of the quartz glass and the result were non-optical. The rest of the remaining concentration, such as x = 0.5 and x = 0.8 were optical and semi-optical respectively. Surface quality were observed from all of the varying concentrations.