晶圆直接键合及室温键合技术研究进展

晶圆直接键合技术可以使经过抛光的半导体晶圆,在不使用粘结剂的情况下结合在一起,该技术在微电子制造、微机电系统封装、多功能芯片集成以及其他新兴领域具有广泛的应用。对于一些温度敏感器件或者热膨胀系数差异较大的材料进行键合时,传统的高温键合方法已经不再适用。如何在较低退火温度甚至无需加热的室温条件下,实现牢固的键合是晶圆键合领域的一项挑战。本文以晶圆直接键合为主题,简单介绍了硅熔键合、超高真空键合、表面活化键合和等离子体活化键合的基本原理、技术特点和研究现状。除此之外,以含氟等离子体活化键合方法为例,介绍了近年来在室温键合方面的最新进展,并探讨了晶圆键合技术的未来发展趋势。

Research Progress of Wafer Direct Bonding and Room-Temperature Bonding Technology

Wafer direct bonding technology allows to bond two polished wafers without any adhesive. It is widely used in microelectronics manufacture, microelectromechanical systems (MEMS) packaging, multifunctional chip integration, and other emerging areas. However, conventional high-temperature bonding methods are no longer applicable for temperature-sensitive devices or dissimilar materials with large thermal expansion mismatches. Low temperature bonding or room-temperature bonding without heating is highly desirable but a challenge in the wafer bonding field. In this article, we focused on several wafer direct bonding methods including fusion bonding, ultra-high vacuum bonding, surface activated bonding and plasma activated bonding. Fundamental principles, technical features and research status of these bonding methods were briefly overviewed. In addition, a fluorine containing plasma activated bonding method was introduced, as an example of recent advances in room-temperature bonding. The future development trend of wafer bonding technology was also addressed.