Silicon interposer with integrated fine-pitch wafer test probes

A wafer test probe, comprising:

• a semiconductor pillar;
• a conductive line isolated from and extending through the semiconductor pillar;
• layers disposed on the semiconductor pillar to form a layer body with an exterior surface and an opening extending into the layer body from the exterior surface, each of the layers comprising dielectric material and conductive material, the conductive material forming an additional conductive line in electrical contact with the conductive line and extending through the layer body;
• blade features disposed on the exterior surface of the layer body in electrical contact with the additional conductive line, the blade features comprising terminal ends that terminate at the opening and that are configured to conductively penetrate into a solder bump;
• and
• a conductive coating disposed on the blade features and the terminal ends thereof.

A method of fabricating a wafer test probe, the method comprising:

• etching an opening into a semiconductor pillar to expose a material of one or more conductive lines electrically isolated from the semiconductor pillar;
• patterning the etching such that the etching forms, in a remainder of the semiconductor pillar, blade features electrically isolated from the semiconductor pillar and terminating at the opening;
• plating the blade features and the material of the one or more conductive lines with a first conductive material;
• and
• plating the first conductive material with a second conductive material, which differs from the first metallic material, which resists oxidation and which is chemically cleanable.

A method of fabricating a wafer test probe, the method comprising:

• forming a semiconductor pillar with one or more conductive lines extending through the semiconductor pillar with electrical isolation;
• etching an opening into an end of the semiconductor pillar to expose a material of the one or more conductive lines;
• patterning the etching such that the etching forms, in a remainder of the end of the semiconductor pillar, blade features electrically isolated from the semiconductor pillar and terminating at the opening;
• plating the blade features and the material of the conductive line with a first conductive material;
• and
• plating the first conductive material with a second conductive material, which differs from the first metallic material, which resists oxidation and which is chemically cleanable.

A method of fabricating a wafer test probe, the method comprising:

• forming a semiconductor pillar with one or more electrically isolated conductive lines;
• building up a layer body on the semiconductor pillar with layers comprising dielectric material and conductive material such that the conductive material forms an additional conductive line electrically contacting the conductive line and extending through the layer body;
• disposing blade features configured to conductively penetrate into a solder bump on the layer body in electrical contact with the additional conductive line;
• etching an opening into the blade features and the layer body;
• and
• disposing a conductive coating on at least the blade features.