Oblique hole etching method

Abstract

The invention provides an inclined hole etching method. The inclined hole etching mechanism comprises steps that according to a horizontal etching step, isotropic etching is mainly carried out, and an opening of a top part of an inclined hole is enlarged, and at the same time, the inclined angle range of the side wall of the inclined hole is controlled; according to a depth etching step, the isotropic etching is mainly carried out, and the depth of the inclined hole is increased, and at the same time, the fine adjustment of the inclined angle and the roughness of the side wall of the inclined hole is carried out. The inclined hole etching method is advantageous in that under a precondition of guaranteeing the inclined angle and the morphology of the ideal inclined hole, the recess problem of the top part of the side wall is solved.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to an oblique hole etching method. Background technique [0002] In recent years, as MEMS devices and systems are more and more widely used in the fields of automobiles and consumer electronics, and the broad prospects of TSV (Through Silicon Etch, through hole etching) in the future packaging field, deep silicon etching technology has gradually become One of the hottest processes in the field of MEMS processing and TSV technology. The etching process of oblique holes is currently an important means to achieve TSV and packaging fields. This is because: for straight holes, especially straight holes with a certain depth-to-width ratio, it will increase the difficulty of PVD filling in the subsequent channel. And the oblique hole (the inclination angle is about 85°) is more conducive to the PVD filling in the back channel. [0003] An existing oblique hole etching method com...

AI Technical Summary

Problems solved by technology

[0008] First, in step one, since the size of the dent formed in the first step of etching is difficult to control, step 3 cannot be accurate enough to just eliminate the dent

Moreover, for deep holes with smaller diameters, the formed depressions are more severe, resulting in that the etching depth after completely removing the depressions cannot meet the process requirements

[0009] Second, the addition of steps two and three makes the entire process complex, and the overall thinning of the substrate in step three may cause the inclination angle or shape of the oblique hole to be destroyed

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