Texas Instruments Corporation

Samuel C Baber

Vernon R Porter

Robert H Havemann

The present invention discloses a method for planarizing contact holes, vias, and other surface depressions, during the fabrication of an integrated circuit structure. Differential thermal conductivities are exploited to selectively remove a deposited film of metal from high-thermal-resistance areas, such as silicon dioxide or other insulators, and not from low-thermal-resistance areas, such as silicon or metal. By repetition of this step, very deep depressions, having a high aspect ratio, are reliably filled.

Metal planarization process

After the extrinsic base region of a bipolar transistor has been formed, and the emitter contact has been patterned and cut, the emitter dopant is deposited or spun on, and the emitter dopant is then driven in using a short pulse of radiant energy. The necessity for high-temperature annealing of the emitter doping is thereby avoided, and the base doping profile is not disturbed by high-temperature annealing steps.

Self-aligned low-temperature emitter drive-in

A method for selectively depositing a composite material over high-thermal-conductivity areas (such as silicon) and not over low-thermal-conductivity areas (such as oxide), which does not require any additional patterning step. A composite material, such as TiW is deposited overall by sputtering. A short pulse of light is then applied, and the composite material over the oxide separates and flakes off, while the composite material over the high-thermal-conductivity area remains in place.

Selective deposition of composite materials

A method for selective removal of metallization in integrated circuits. A uniform metal film is applied over a patterned resist layer. A short pulse of radiant energy is then applied to the whole surface of the metal film. The resist underneath the metal film is locally heated enough to cause outgassing, which breaks the mechanical bond between the metal film and the resist. The metal film over the patterned resist layer is then removed, leaving the deposited metal film in place over areas which were not covered by the resist film.

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Richardson, TX, United States of America

Samuel C Baber