Patent ID: 8808800

Claim:
In a method of forming a multi-layer three-dimensional structure, comprising: (A) forming a plurality of successive layers of the structure with each successive layer, except for a first layer, adhered to a previously formed layer and with each successive layer comprising at least two materials, one of which is a structural material and the other of which is a sacrificial material, and wherein each successive layer defines a successive cross-section of the three-dimensional structure, and wherein the forming of each of the plurality of successive layers includes: (i) depositing a first of the at least two materials; (ii) depositing a second of the at least two materials; (iii) planarizing the at least two materials; and (B) after the forming of the plurality of successive layers, separating at least a portion of the sacrificial material from the structural material to reveal the three-dimensional structure, wherein the improvement comprises: in association with the formation of a given one of the successive layers, depositing a primary structural material in a lateral region of the given one of the successive layers, thereafter planarizing the primary structural material to a height that bounds the desired height of the given one of the successive layers and such that at least a portion of the primary structural material of the given one of the successive layers is work hardened, and thereafter etching into the planarized primary structural material of the given one of the successive layers to form one or more openings that extend into the given one of the successive layers in a least a portion of the lateral region to remove at least a portion of the work hardened primary structural material such that a majority of the given one of the successive layers in the lateral region is formed, and after the etching, depositing structural material into the one or more openings to form an additional part of the given one of the successive layers, wherein the removal of work hardened primary structural material by etching and then depositing of structural material results in a structure having less internal stress than the structure would otherwise have.