Germany – Semiconductors – Plasma-Ätzanlage - PR1241915-2270-W

Many areas of semiconductors, MEMS, and 3D integration technologies - such as microfluidics, physical, optical, and chemical sensors, and emerging quantum mechanical devices such as so-called Qubits and their integration into silicon substrates - utilize the excellent properties of silicon. In particular, high-precision structuring methods have been developed for these applications. Micro- and nanochannels, membranes, valves, cantilevers, and through-silicon vias are manufactured using Si deep reactive ion etching (Si-DRIE) technology. As a standard etching gas, SF6 is employed in Silicon Deep Reactive Ion Etching (Si-DRIE) processes. SF6 is a potent greenhouse gas with a high global warming potential (GWP) of 25.300 CO2-equivalents. Although the semiconductor industry currently benefits from an exemption regarding SF6 usage, the duration of this exemption remains uncertain. Consequently, the identification of alternative gases to replace SF6 is becoming more important. One promising alternative is F2 gas mixtures. However, their implementation requires specialized modifications to both gas infrastructure and process kits. Hence, in addition to its fluorine compatibility, the requirements for the novel etching system should include scalability and a minimized process chamber volume compared to conventional plasma etching systems. This reduction in chamber volume decreases the total gas flow required, thereby enabling nearly complete gas utilization while minimizing gas-wall interactions. Consequently, faster gas switching times can be achieved in Bosch processes. A key feature of this new developed etching system is its "Green Production" concept, which focuses on the minimization and prevention of environmentally harmful gases. Furthermore, the system enables straightforward scaling of substrate sizes from 150 mm to 200 mm.