University of California

Ke Luo

Arunava Majumdar

Jie Lai

Nanometer holes can be reliably and repeatedly defined in the tips of cantilevered probes and used in various types of scanning multiprobe microscopy by defining the hole within a layer disposed on the tip using focused electron or ion beams. The drilling of the hole on the apex of the tip and is stopped just as soon as the hole is defined through an overlying insulating layer under which lies a metallic or semiconductor layer at the apex. The hole is then backfilled with another metallic or semiconductor layer so that an active electrical junction is formed between the two layers through the hole in the insulating layer. The hole may be defined in conductive layers in various combinations with oxide layers, other metal layers and semiconductor materials to define Schottky diodes, thermocouple junctions, near-field optical detectors, and atomic force tips. As a result, two or more physical interactions may be simultaneously exploited between the fabricated tip and the scanned sample from which a scanned image may be produced.

Use of focused ion and electron beams for fabricating a sensor on a

Nanometer holes can be reliably and repeatedly defined in the tips of cantilevered probes and used in various types of scanning microscopy by voltaicly defining the hole within a conductive layer disposed on the tip. The field strengths of the apex of the tip are sufficient to cause evaporation of the metal or conductive material from the apex onto an opposing sample substrate. The hole opens on the apex of the tip and is self-limited by the inherent threshold voltage strength required for vaporization, which voltage strength falls off rapidly from the tip. The hole may be defined in conductive layers in various combinations with oxide layers, other metal layers and semiconductor materials to define Schottky diodes, thermocouple junctions, near-field optical detectors, and atomic force tips. As a result, two or more physical interactions may be simultaneously exploited between the fabricated tip and the scanned sample from which a scanned image may be produced.

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Goleta, CA, United States of America

Ke Luo