Layered intermetallic compounds and stress evolution in Sn and Ni(P) films

Abstract

In situ measurements of stresses due to the phase transformation in Sn and Ni(P) films were analyzed relating to the formation of layered intermetallic compounds such as Ni3Sn4, Ni3Sn2, Ni3P, and the crystallization of Ni(P) films. When Sn/Ni(11.7P) films were heated up to 480 °C, the first tensile stress developed due to formation of Ni3Sn4 and Ni3P around 220 °C, and the second one appeared at 335 °C due to formation of Ni3Sn2 as well as the self-crystallization of Ni(11.7P). For Sn/Ni(3P), a tensile stress developed mildly with the temperature between 300 and 410 °C due to formation of Ni3Sn2 and precipitation of Ni3P. The onset temperatures of self-crystallization of Ni(P) and Ni3P precipitation decreased due to the Ni–Sn reaction.