High-temperature Resistant Wafer-level Temporary Bonding by W Release Layer for Diamond Growth

Temporary bonding and debonding (TBDB) technologies are crucial for obtaining high-density, ultra-thin, and ultra-small 2.5D/3D integrated products. Traditional polymer-based temporary bonding adhesives have defects such as high selectivity for bonding materials and low tolerance to high temperatures. Although direct dielectric bonding exhibits a high temperature resistance limit, it typically results in permanent bonding. Therefore, leveraging the principle of metal thermal compression bonding (TCB), this study developed a high-temperature-resistant W metal temporary release layer. With an interface layer of less than 100 nm, the warpage of ultra-thin wafers can be effectively reduced. The temperature resistance limit of this process can reach the diamond growth temperature range of 700-900 °C, and nondestructive debonding can be easily achieved. This process is expected to support and enable the transfer of diamond deposition on the surface of various ultra-thin semiconductor materials in the future.