Enhancement of through Silicon via Sidewall Quality by Nanosecond Laser Pulses with Chemical Etching Process

Through-silicon via (TSV) is an emerging technology for three-dimensional integrated circuit, system in package, and wafer level packaging applications. In this study, a wet chemical etching (WCE) process has been employed to enhance the sidewall quality of TSVs fabricated using nanosecond (ns) laser pulses. Experimental results show that the TSV sidewall roughness can be markedly reduced, from micrometer scale to nanometer scale. We concluded that the proposed method would enable semiconductor manufactures to use ns laser drilling for industrial TSV fabrication as the desired TSV sidewall quality can be achieved by incorporating the WCE process, which is suitable for mass production.