Arrangement of microstructures
View Patent ↗A method referred to as a “cellular damascene method” utilizes a multiplicity of regularly arranged closed cavities referred to as “cells”, which are produced in a patterning layer. The dimensions of the cavities are on the order of magnitude of the microstructures to be produced. Selected cavities are opened by providing a mask and partitions situated between adjacent opened cavities are removed to provide trenches and holes which are filled with the material of the microstructure to be fabricated. Protruding material is removed by means of a chemical-mechanical polishing step. The microstructures are, in particular, interconnects and contact holes of integrated circuit.
1. An arrangement of microstructures having a patterned layer in which a multiplicity of closed cavities and a multiplicity of microstructures are arranged, the closed cavities being presented in a grid point of a predetermined raster and the microstructures running along the connecting lines that connect the grid points, the closed cavities having a given lateral extent in at least one direction and the lateral extent of the microstructure in this direction corresponds to at last twice the lateral extent of the cavities.
2. An arrangement according to claim 1 , wherein partitions of individual thicknesses are arranged between adjacent cavities and between cavities in microstructures adjacent thereto.
3. An arrangement according to claim 1 , wherein grid points have a distance D, the lateral extent of the closed cavities is B and the lateral extent of the microstructure is n·D+B, wherein n is a natural number.
4. An arrangement according to claim 1 , wherein the patterned layer comprises at least first and second layers made of different materials, said second layer lying on said first layer, and the cavities run at least in the first layer and the microstructures run at least in both layers.
5. An arrangement according to claim 4 , wherein the material of the first layer is a silicon nitride and the material of the second layer is a silicon oxide.
6. An arrangement according to claim 4 , wherein the cavities are closed with a covering layer grown selectively on the material of the second layer.
7. An arrangement according to claim 1 , wherein the microstructures are interconnects.
8. An arrangement according to claim 1 , wherein the microstructures are of a material selected from a group consisting of metal, metal alloys and copper.