Method of manufacturing mems device

Abstract

A method of manufacturing an MEMS device includes: forming a covering structure having an MEMS structure and a hollow portion, which is located on a periphery of the MEMS structure and is opened to an outside, on a substrate; and performing surface etching for the MEMS structure in a gas phase by supplying an etching gas to the periphery of the MEMS structure from the outside.

1 . A method of manufacturing an MEMS device, the method comprising:
 forming a covering structure having an MEMS structure and a hollow portion, which is located on a periphery of the MEMS structure and is formed by eliminating a sacrifice layer using etching solution together with releasing the MEMS structure and is opened to an outside, on a substrate; and   performing surface etching for the MEMS structure by supplying an etching gas to the periphery of the MEMS structure from the outside.   
     
     
         2 . The method of manufacturing an MEMS device according to  claim 1 , further comprising:
 performing a test on operating characteristics of the MEMS structure and determining whether to perform in addition the surface etching by comparing a result of the test with a reference value, after the forming of the covering structure on the substrate.   
     
     
         3 . The method of manufacturing an MEMS device according to  claim 2 ,
 wherein the MEMS structure has a movable portion that can be operated, and   wherein, in the performing of a test on operating characteristics, the test is performed in a state in which the movable portion is operated.   
     
     
         4 . The method of manufacturing an MEMS device according to  claim 1 , wherein the MEMS structure is configured by a silicon layer, and the etching gas is XeF2. 
     
     
         5 . The method of manufacturing an MEMS device according to  claim 2 ,
 wherein the performing of a test on operating characteristics is performed in parallel with the surface etching during the performing of surface etching for the MEMS structure, and   wherein the surface etching is stopped when the operating characteristics correspond to a range corresponding to the reference value.   
     
     
         6 . The method of manufacturing an MEMS device according to  claim 2 ,
 wherein the MEMS device is an MEMS resonator that vibrates the movable portion of the MEMS structure, and   wherein the operating characteristics are frequency characteristics.   
     
     
         7 . The method of manufacturing an MEMS device according to  claim 6 ,
 wherein the performing of a test on operating characteristics is performed in parallel with the surface etching during the performing of surface etching for the MEMS structure by vibrating the movable portion all the time, and   wherein the surface etching is stopped when the operating characteristics correspond to the range corresponding to the reference value.   
     
     
         8 . The method of manufacturing an MEMS device according to  claim 1 , further comprising: closing an opening of a lid body after the performing of surface etching for the MEMS structure,
 wherein the forming of a covering structure includes:   forming the MEMS structure together with a first sacrifice layer on the substrate;   forming a second sacrifice layer that configures at least a part of the covering structure on the upper side of the MEMS structure;   forming the lid body that has the opening on the second sacrifice layer; and   eliminating the first sacrifice layer and the second sacrifice layer through the opening of the lid body, releasing the MEMS structure, and forming the hollow portion on the periphery of the MEMS structure, and   wherein the performing of surface etching for the MEMS structure is performed by introducing the etching gas into an inside of the hollow portion through the opening of the lid body.