Process for deuterium passivation and hot carrier immunity
AssigneeLucent Technologies Inc.
InventorsSundar S. Chetlur, Pradip K. Roy, Anthony S. Oates, Sidhartha Sen, Jonathan Z-N. Zhou
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Abstract
A process sequence for forming a semiconductor device utilizes a passivation annealing process using deuterium which enhances immunity to hot carrier effects and extends device lifetime. The process sequence is carried out prior to the introduction of metal conductive films to the device. The process sequence includes a three-step passivation, de-passivation, re-passivation sequence and utilizes a barrier film to encapsulate deuterium molecules in the vicinity of a gate oxide, during the de-passivation operation.
Claims21
A process for passivating traps within a semiconductor structure of a semiconductor device, comprising the steps of:
- (a) providing a semiconductor structure comprising a semiconductor substrate including a surface having an oxide film formed thereon;
- (b) after step (a), annealing the structure in an environment including deuterium;
- (c) after step (b), forming a barrier film over at least the oxide film, the barrier film at least indirectly encapsulating the oxide film and being impervious to deuterium, the barrier film chosen from the group consisting of titanium, titanium nitride, tungsten, tungsten nitride, tantalum, and tantalum nitride,
- (d) after step (c), sintering at a sintering temperature greater than about 700° C., and
- (e) after step (d), further annealing the structure at a further anneal temperature being less than the sintering temperature.
A process for passivating traps within a semiconductor structure of a semiconductor device, comprising the steps of:
- (a) providing a semiconductor structure comprising a semiconductor substrate including a surface having an oxide film formed thereon;
- (b) after step (a), annealing the structure in an environment including deuterium at a passivation anneal temperature within the range of 400° C. to 700° C.;
- (c) after step (b), forming a barrier film over at least the oxide film, the barrier film at least indirectly encapsulating the oxide film and being impervious to deuterium, the barrier film chosen from the group consisting of titanium, titanium nitride, tungsten, tungsten nitride, tantalum, and tantalum nitride,
- (d) after step (c), sintering at a sintering temperature greater than about 700° C., and
- (e) after step (d), further annealing the structure at a further anneal temperature being less than the sintering temperature.
Dependencies are inferred from the claim text.