In order to solve problem that structure forming can not finish easily in deep groove

an analytical expression of step width and depth of maskless etching is derived based on theory of anisotropic etching of crystalline silicon in KOH solution. The etching rate of{ 311} surface and{ 100} surface of the crystalline silicon is determined by process experiments; a maskless etching forming process flow for chip fabrication of sandwich micro acceleration sensor is proposed

and accurate forming of cantilever beam during fabrication in deep groove is realized

a micro acceleration sensor for ± 100 gnrange is developed. Sample tests show that the relative precision of micro acceleration sensor fabricated by maskless etching technique is prior to 6 × 10

-5

and sensitivity is17. 78 m V / g

n

.