Process for fabricating packaged MEMS devices at wafer level

摘要

A method of manufacturing (100; 100A; 100B) comprising the steps of: providing (110) a semiconductor substrate (300) with a wiring layer stack (304) having recesses (302) on a first major surface area (300-1) of said semiconductor substrate (300) first main surface region (300-1) of the semiconductor substrate (300), MEMS devices (306) are exposed in the recesses (302) of the wiring layer stack (304), and via contacts (310) projecting on metallization regions (308) of the wiring layer stack (304) depositing (130) a middle stage cured b-stage material layer (312) on the wiring layer stack (304) so that the recesses (302) in the wiring layer stack (304) are separated from the b-stage material layer (312) ) are covered and further introduced the vertically protruding via elements (310) in the b-stage material layer (312) we wherein the applied b-stage material layer has a dimensional stability such that, in the application of the b-stage material layer (312), cavities above the MEMS devices are retained in the recesses of the wiring layer stack, hardening (150) the b-stage Material layer (312) to obtain a cured b-stage material layer (312), thinning (170) the cured b-stage material layer (312) to expose end surface areas (310-1) of the via elements (310), and applying (190) a redistribution layer (RDL) structure on the thinned, cured b-stage material layer (312) to provide electrical connection between the wiring layer stack (304) and the RDL structure (314) via the via elements (310) ) to obtain.