Verfahren zum Aetzen von Strukturen in einer Siliziumschicht

In a method of etching structures in a silicon layer using a masking layer, the etchant consists of a mixture of monoethanolamine- dimethyl sulphoxide and water, preferably 10-75 (especially 50) vol.% of a mixture of 60-80 (especially 70) vol.% monoethanolamine and 20-40 (especially 30) vol.% dimethyl sulphoxide in water. USE - Especially in microelectronics and micro-mechanics. ADVANTAGE - The etchant has high selectivity wrt. SiO2, so that SiO2 can be used as masking material instead of materials such as SiC which are not usually used in CMOS technology, permitting combined production of micro-mechanical sensors and microelectronic devices.