Recent advances in silicon etching for MEMS using the ASE™ process

In the ongoing enhancement of MEMS applications, the STS Advanced Silicon Etch, ASE™, process satisfies the demanding requirements of the industry. Typically, highly anisotropic, high aspect ratios profiles with fine CD control are required. Selectivities to photoresist of 150:1 with Si etch rates of up to 7 μm/min are achievable. Applications range from shallow etched optical devices to through wafer membrane etches. This paper details some of the fundamental trends of the ASE™ process and goes on to discuss how the process has been enhanced to meet product specifications. Parameter ramping is a powerful technique used to achieve the often conflicting requirements of high etch rate with good profile/CD control. The results are presented in this paper.