Method for making a planar suspended microstructure, using a sacrificial layer of polymer material and resulting component

Abstract

Production process of a flat suspended micro-structure using a sacrificial layer of polymer material and component obtained thereby The process successively comprises deposition of a sacrificial layer ( 2 ) of polymer material, deposition, on at least a part of the substrate ( 1 ) and of the front face of the sacrificial layer ( 2 ), of an embedding layer ( 6 ), the thickness whereof is larger than that of the sacrificial layer ( 2 ), and planarization so that the front faces of the sacrificial layer ( 2 ) and of the embedding layer ( 6 ) form a common flat surface. A formation layer ( 3 ) of a suspended structure ( 5 ) is deposited on the front face of the common flat surface. Planarization can comprise chemical mechanical polishing and etching of the embedding layer ( 6 ). Etching of the sacrificial layer ( 2 ) can be performed by means of a mask formed on the front face of a layer of polymer material eliminated during the planarization step.

1 .- 7 . (canceled)  
   
   
       8 . Production process of an integrated micro-system type component, comprising a flat suspended micro-structure, using a sacrificial layer of polymer material deposited on a substrate and having side walls confining the flat suspended structure, process successively comprising a planarization step, a deposition step of a formation layer of the suspended structure, an etching step of at least one opening of the formation layer up to the level of the front face of the sacrificial layer and a dry etching step of the sacrificial layer, process comprising, between deposition of the sacrificial layer and the planarization step, a deposition step, on at least a part of the substrate and of the front face of the sacrificial layer, of an embedding layer presenting a larger thickness than the thickness of the sacrificial layer, so that, after the planarization step, the front faces of the sacrificial layer and of the embedding layer form a common flat surface, the formation layer of the suspended structure being deposited on the front face of the common flat surface.  
   
   
       9 . Production process according to  claim 8 , wherein the planarization step comprises chemical mechanical polishing.  
   
   
       10 . Production process according to  claim 8 , wherein the planarization step successively comprises a chemical mechanical polishing sub-step of the embedding layer and an etching sub-step of the embedding layer so that the front faces of the sacrificial layer and of the embedding layer form a common flat surface.  
   
   
       11 . Production process according to  claim 8 , wherein the side walls of the sacrificial layer are confined by etching by means of a mask formed on the front face of a layer made from polymer material by deposition, lithography and etching of a temporary layer, deposition of the embedding layer being performed on the assembly formed by the sacrificial layer and the mask, the mask being eliminated in the course of the planarization step.  
   
   
       12 . Production process according to  claim 11 , wherein the planarization step comprises an etching step of the mask.  
   
   
       13 . Production process according to  claim 8 , wherein, the component comprising salient elements on the substrate, the process successively comprises, before deposition of the sacrificial layer, deposition on at least one zone of the substrate designed to be covered by the sacrificial layer and comprising salient elements, of a base layer presenting a larger thickness than the thickness of the salient elements, and an additional planarization step, by chemical mechanical polishing, of the base layer so that the front faces of the base layer and of the salient elements form a common flat surface.  
   
   
       14 . Component, produced by the process according to  claim 8 , wherein the two faces of the formation layer of the suspended structure are totally flat.