Abstract: In order to meet the requirements of compatibilizing substrate thickness and interlayer electrical interconnection in application of the through silicon via (TSV) interposer (such as silicon microchannel), the preparation process of TSV interposer with depth of more than 500 μm is developed, which has broken through the key technologies of high-depth TSV etching. The aperture of the prepared TSV interposer is 80 μm, the depth is more than 500 μm, the depth to width ratio is more than 6∶1, the perpendicularity is more than 89.85° and the scallop can be controlled within 250 nm. The TSV interposer, which is prepared based on the via forming technology, has favorable film uniformity and electrical interconnection and can meet the application requirements of TSV interposer with high mechanical strength, deep cavities and low cost.