Effects of Electromigration on the Bi2Te3/Sn Interfacial Reactions

• Main Authors: Hsing-Ting Chan, 詹幸婷
• Other Authors: Chih-Ming Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/95630625534641057081

碩士 === 國立中興大學 === 化學工程學系所 === 103 === Since the concept of energy saving and carbon reduction becomes general, thermoelectric materials which can transform thermal energy into electric energy mutually get popular in recent year. In many kinds of thermoelectric material, Bismuth Telluride has high figure-of-merit(ZT) beyond 1 . Besides, through doping Selenium or Antimony in Bismuth Telluride, the n-type and p-type semiconductor can be realized, respectively. Recently, most researches of thermoelectric material focus on enhancing figure-of-merit and manufacturing method. Moreover, Few researches analyze about package process problems after thermoelectric chip assembling. This research adopts zone-melted Bi2Te3 substrates which is layer structure material to join with Sn solder in perpendicular or parallel to the layer direction and compares electrical stressing of the sandwich modules Sn/different layer direction Bi2Te3/Sn with thermal annealing of the sandwich modules. The interface of Sn/different layer direction p-type Bi2Te3/Sn has SnTe IMC and Sn(Sb,Te) IMC. On the other hand, The interface of Sn/different layer direction n-type Bi2Te3/Sn include SnTe IMC and BixTey IMC. IMC structure and thickness of different layer direction n-type Bi2Te3 modules are all the same. According to different layer direction, p-type module formed different structure IMC. When electrical stressing time increase, Sn3Sb2 particles appear on the SnTe layer and their distributions along with perpendicular layer p-type modules at the cathode side.Sn/p-type Bi2Te3/Sn modules at the cathode side are much thicker IMC layer than thermal annealing, but they contray to the anode side. Therefore, p-type Bi2Te3 modules are affected electromigration and thermoelectric effect at the same time. Current stressing of Sn/n-type Bi2Te3/Sn modules are the same thick IMC layer with thermal annealing modules, so n-type Bi2Te3 modules are affected by thermoelectric effect more than electromigration.