Study of microvias fabrication on AlN substrates by using a femtosecond laser
曾雅欣1*, 朱慧心1, 曾勝陽1, 羅志偉1, 王智2, 姜智豪2, 郭養國2
1電子物理系, 國立交通大學, 新竹市, Taiwan
2化學所, 中科院, 桃園縣, Taiwan
* presenting author:曾雅欣,
High thermal conductivity and high electrical resistivity of ceramics make them ideal interposer materials for three-dimensional integrated circuits. However, the current etching process utilized in the semiconductor industry for fabricating through silicon via cannot be used in ceramic materials. In addition, because of the hardness, fabricating microvias by using micromachining is also difficult. Fortunately, the extremely high peak power of a femtosecond laser pulse ablates most materials without thermal effect. In this poster, the femtosecond laser pulses with different parameters, such as average power, polarization, spot size, converging angle and focus position, are utilized to produce microvias on aluminum nitride substrates. The experimental results show that with a 10x objective lens, 0.4 cm iris aperture, 125 mW output power, 1 s exposure time, 50 μm focusing depth and circular polarization, a microvia on an aluminum nitride substrate with an optimal diameter of approximately 10 μm and a taper of approximately 0.03 % can be produced.

Keywords: aluminum nitride substrate, femtosecond laser, microvias