Carbon nanotube contact structures

A probe card assembly for testing a semiconductor device having contact pads, the probe card assembly comprising:

• a substrate;
• a plurality of interconnection elements mounted on the substrate and extending upwardly therefrom;
• an electrical connection formed between each interconnection element and a conductor in the substrate;
• and
• a contact element electrically connected to each interconnection element and spaced apart from the substrate, wherein each said contact element comprises:
• an electrically conductive base attached to one of the interconnection elements, and
• a plurality of carbon nanotubes attached to and extending away from a surface of the base.

A method of making a contact structure comprising:

• defining an opening in a sacrificial layer;
• defining a layer of carbon nanotubes on a surface of the opening;
• depositing a metallic layer over the carbon nanotubes;
• and
• removing the sacrificial layer, wherein:
• the defining a layer of carbon nanotubes on a surface of the opening comprises growing carbon nanotubes in the opening, and
• growing the carbon nanotubes in the opening comprises depositing a catalyst in the opening and growing a film of carbon nanotubes on the catalyst.

A contact structure comprising:

• an electrically conductive base having a surface;
• a plurality of carbon nanotubes attached to and extending away from the surface of the base;
• and
• a plurality of metal structures attached to the surface of the base and dispersed among the nanotubes, the metal structures extending from the surface away from the base.

A method of making a contact structure comprising:

• defining a pattern on a base;
• growing a carbon nanotube film on the defined pattern but not outside of the defined pattern;
• creating a plurality of metal structures on the base outside of the defined pattern;
• affixing a metal plate to the tops of the film and the structures;
• and
• removing the base.