Reactive ion etching of Cr-doped Sb

Cr doped Sb 2 Te 3 (CST) was considered to be a potential phase-change material mainly due to its fast phase transition and high thermal stability. To manufacture high-integration phase change memory devices, etching technology of CST films is indispensable. Herein we investigated the properties of reactive ion etching of CST thin films in CHF 3 /O 2 -based plasma. The etch parameters such as etch rate, selectivity and surface roughness were optimized by varying the CHF 3 /O 2 gas mixture ratio to explore the effect of etching gas on etching quality. We observed that etching of CST films was optimized under the condition of CHF 3 /O 2 gas ratio of 40/10, RF power of 200 W, and chamber pressure of 10 mTorr, i.e. the etch rate was up to 101.8 nm/min, the selectivity to photoresist was 0.78 and the surface was smooth. The etching mechanism and residual products in the etching process were also explored by X-ray photoelectron spectroscopy (XPS). Under the optimized conditions, a highly efficient and low-damage reactive ion etching method for CST materials is obtained. Display Omitted • The CHF 3 /O 2 ratio was optimized for the RIE of novel phase change material Cr-SbTe and its influence mechanism was analyzed. • The optimal process of Cr-SbTe etching with high etch rate, high selectivity and low surface roughness were achieved. • The etch mechanism of Cr-SbTe was inferred by X-ray photoelectron spectroscopy and depth profiling.