Improving the sidewall quality of nanosecond laser-drilled deep through-silicon vias by incorporating a wet chemical etching process

Through-silicon vias (TSVs) are thought to be the essential process of the next-generation packaging technologies such as three-dimensional integrated circuit, system in package and wafer-level packaging. This Letter investigated the formation quality of deep TSVs using green nanosecond laser drilling process. Moreover, a wet chemical etching (WCE) process was employed to improve the sidewall quality of deep TSVs fabricated using green ns laser pulses. Experimental results show that the TSV sidewall roughness can be markedly reduced, from micrometre to nanometre scale. 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.