Method for producing micromechanical structures and a micromechanical structure

Abstract

A method for producing micromechanical structures, in which a functional layer is deposited onto a sacrificial layer, and the sacrificial layer is removed again for the production of at least one mechanical functional element, which is characterized by a surface barrier layer, with which the functional layer begins on the sacrificial layer, and which has a different state from the remaining functional layer, is also removed at least to a considerable part, or, on the functional layer, one layer or a plurality of layers having at least approximately the same properties with respect to stress in the layer or layers such as the surface barrier layer is(are) applied. Additionally, a micromechanical structure having a functional layer in which the functional layer is constructed in such a way that the stresses are neutralized or no stress gradient appears.

1 . A method for producing micromechanical structures comprising: 
 depositing a functional layer onto a sacrificial layer;    removing the sacrificial layer again, for the production of at least one mechanical functional element; and    removing, at least to a considerable part, a surface barrier layer, with which the functional layer on the sacrificial layer begins, and which has a different state from a remaining functional layer.    
   
   
       2 . The method according to  claim 1 , further comprising: 
 applying the functional layer in a composition of the surface barrier layer as seen in a direction of the remaining functional layer; and    etching at least one part of the surface barrier layer at least initially selective to at least one of the surface barrier layer and the remaining functional layer.    
   
   
       3 . The method according to  claim 2 , further comprising: 
 depositing the functional layer, in at least one partial area of the surface barrier layer, all the way into the remaining functional layer, made of SiGe having a higher proportion of germanium than 65% to 70%, but less than 100%; and    reducing the germanium proportion during the depositing for the remaining functional layer, to a proportion of less than 65% to 70%.    
   
   
       4 . The method according to  claim 1 , further comprising applying the functional layer completely in a composition which demonstrates no, or only a weak selectivity for the sacrificial layer.  
   
   
       5 . The method according to  claim 1 , further comprising applying to the functional layer at least one layer having at least approximately the same properties with respect to a stress in the at least one layer, with which the functional layer begins on the sacrificial layer and which has a different state from the remaining functional layer.  
   
   
       6 . The method according to  claim 5 , wherein the at least one layer includes the surface barrier layer.