The fabrication of GaAs-based optoelectronic ridge-waveguide devices requires deposition of a topside-contact metallization for proper device operation. Fabrication delays occurring during the processing of TiAu-contact pads have been linked to poor adhesion and metal blister formation, factors that negatively affect the final device yield. In this study, we examined sputter-deposited Ti and Au films to determine the impact of film-thickness process control and film stress as measured by wafer bow. We theorized that competing stress relaxation forces between the Ti and Au films would produce a post-deposition change in wafer bow, which affects the Au film, setting the stage for blister creation. We now report the development of a reduced-stress sputter-deposited TiAu-contact metallization and demonstrate the utility of the modified process with fabrication of blister-free ridge-waveguide devices with high device yield.

基于GaAs的光电脊形波导器件的制造需要沉积顶侧接触金属层，以确保器件正常运行。TiAu接触垫的加工过程中出现的制造延迟与不良的附着力和金属气泡形成有关，这些因素会对最终器件的成品率产生负面影响。在这项研究中，我们检查了溅射沉积的Ti和Au薄膜，以确定薄膜厚度工艺控制和薄膜应力（通过晶圆弓测量）的影响。我们的理论是，Ti和Au薄膜之间竞争的应力松弛力将在晶圆弓形中产生沉积后变化，从而影响Au薄膜，从而为产生气泡提供了条件。