Chemically enhanced focused ion beam micro-machining of copper
AssigneeNorth Carolina State University
InventorsPhillip E. Russell, Dieter P. Griffis, Juan Carlos Gonzales Perez
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Abstract
A method of micromachining a copper layer on a substrate is carried out by maintaining the substrate in a vacuum, bombarding a portion of the substrate with a focused particle beam from a particle source, and exposing the substrate to a supply of organic chloride or hydroxide during particle bombardment. The organic chloride or hydroxide concentration at the substrate is an amount sufficient to enhance the relative removal of the copper layer by decreasing the removal of the dielectric or increasing the removal of the copper or a combination of both.
Claims20
A method of micromachining copper on a substrate, comprising the steps of:
- bombarding a portion of the copper with a charged particle beam from a particle source;
- and
- exposing the substrate to a supply of organic hydroxide during particle bombardment, the organic hydroxide concentration at the substrate being sufficient to enhance removal of the copper.
A method of selectively removing a copper material from a substrate to expose a neighboring layer of a second material, the method comprising:
- maintaining the substrate in a vacuum;
- bombarding with a charged particle beam a portion of the substrate having a copper material neighboring a second material;
- and
- exposing the portion of the substrate to organic hydroxide during particle bombardment of the substrate, the copper layer having a sputter etch rate that is increased by the presence of organic hydroxide vapor and the second material having a sputter etch rate that is increased by the presence of organic hydroxide vapor at a lesser rate than that of the copper layer to the degree that the sputter etch rate of the copper material is relatively increased, thereby selectively sputtering the copper material compared with the second material.
A method of shaping features of a surface of a solid object having the surface, said method comprising the steps of:
- positioning said object within an enclosed chamber;
- supplying organic hydroxide vapor within said chamber so that organic hydroxide is adsorbed onto the exposed surface of said object for enabling an induced chemical reaction between the organic hydroxide and a copper layer at said surface;
- generating a focused particle beam;
- and
- directing said beam toward said surface for removal by sputtering of a portion of the copper layer, the particle-beam induced chemical reaction between the organic hydroxide and the copper layer increasing the sputtering rate of the copper layer relative to the sputtering rate of the surface.
A method of chemically-enhanced particle beam machining of a copper layer surrounded by dielectric on a substrate for cross-sectional analysis, comprising:
- applying an organic hydroxide to the substrate;
- and
- bombarding with a focused particle beam a portion of the substrate including thereon a copper layer to expose for examination a cross section of the copper layer;
- with said organic hydroxide applied to said substrate at a concentration sufficient to enhance removal of said copper layer relative to removal of the dielectric.
A method of selectively removing a copper material from a substrate to expose a neighboring layer of a second material, the method comprising:
- maintaining the substrate in a vacuum;
- bombarding with a charged particle beam a portion of the substrate having a copper material neighboring a second material;
- and
- exposing the portion of the substrate to organic hydroxide during particle bombardment of the substrate, the copper layer having a sputter etch rate that is decreased by the presence of organic hydroxide vapor and the second material having a sputter etch rate that is more greatly decreased by the presence of organic hydroxide vapor than that of the copper layer such that the sputter etch rate of the copper material is relatively increased, thereby selectively sputtering the copper material compared with the second material.
Dependencies are inferred from the claim text.