Asymmetrical Heating Behavior at Ni/Doped-Si Junctions for Soi Structures

Abstract

With an increasing component density and shrinking feature size in integrated circuit (IC) chips, the heat dissipation issue on the IC chips becomes increasingly important because of device performance and reliability concerns. The heating behavior at Ni/doped-Si junctions, which depends on Joule heating, Peltier effect and heat conduction, is explored in the study. A semiconductor-on-insulator (SOI) structure is used to obtain thermal isolation of the test specimen. The Si channel of 720 μm × 25 μm was lithographically defined and implanted with As+ and BF₂⁺ dopants at a dose of 5×10¹⁵ ions/cm², respectively. By applying a current through a Ni contact/doped-Si/Ni contact structure and measuring the resistance of the doped Si channel near the cathode and the anode ends, we found an obvious asymmetrical heating behavior at the two ends, depending on the dopant type and post-implanatation annealing condition. The Seebeck coefficients of doped Si were measured to be about 140 μV/K and 80 μV/K for BF₂⁺ - doped Si and As⁺-doped Si, respectively.