Oxidation Resistance Characteristics of Silicon Thermal Nitride Films
| Autor: | Ming‐Kwang Lee, Ching‐Yuan Wu, Chin‐Tay Shih, Chin‐Tang Chen, Chwan‐Wen King |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Thermal oxidation
Materials science Silicon Renewable Energy Sustainability and the Environment Silicon dioxide Inorganic chemistry Nanocrystalline silicon chemistry.chemical_element Nitride Condensed Matter Physics Thermal diffusivity Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Silicon nitride Chemical engineering Materials Chemistry Electrochemistry LOCOS |
| Zdroj: | Journal of The Electrochemical Society. 130:458-462 |
| ISSN: | 1945-7111 0013-4651 |
| DOI: | 10.1149/1.2119731 |
| Popis: | The oxidation resistance characteristics of silicon thermal nitride films are studied theoretically and experimentally. A four-layer model for the oxidation resistance kinetics has been developed in general, and the oxidation resistance time has been defined and used to evaluate the oxidation resistance of high structure density films on silicon in oxygen ambient. The thermal silicon nitride films prepared by nitridizing the silicon surface in ammonia ambient have been used to justify the developed oxidation resistance model, and reasonable agreement between the developed model and the oxidation resistance characteristics of the fabricated thermal silicon nitride films have been obtained. Based on the developed model, the diffusivity and diffusion length of the oxidant species in the thermal silicon nitride films have been deduced and their activation energies are estimated to be -2.091 and -0.672 eV, respectively. Silicon nitride has been an important material in the fabrication of high performance integrated circuits and devices due to its higher structure density which exhibits strong oxidation resistance and barrier against diffusion of impurities (1-3). Recently, several investigators (4-6) have reported that higher structure density films can be prepared by directly nitridizing the silicon surface in ammonia gas or nitrogen. Some important applications of the as-grown thermal nitride films in MOSFET (7) and electrically alterable ROM (8) have also been reported. The major difference between the thermal nitridation and the thermal oxidation is that the as-grown thermal nitride films have higher structure density, so "self-limiting" growth can easily occur for the thermal nitridation of the silicon surface in nitrogen or ammonia ambient. The growth kinetics of the as-grown thermal nitride film in a~mmonia or nitrogen gas has been proposed by us (9). It has been shown that the self-limiting growth of the thermal silicon nitridation in ammonia or nitrogen gas is mainly due to the fact that the characteristic diffusion length of the nitridant species in the as-grown thermal nitride film is much smaller than the thickness of the as-grown films. The characteristic diffusion length of the nitridant species has been estimated to be smaller than 10A for nitridation temperatures below 1200~ In this paper an oxidation resistance model for the silicon thermal nitride films in oxygen ambient is developed to interpret the oxidation resistance characteristics observed from the silicon thermal nitride films oxidized in dry O2 ambient. A characteristic time which is called the oxidation resistance time is defined and used to evaluate the structure density of the asgrown silicon thermal nitride films. Based on comparisons between the developed model and the oxidation resistance characteristics of the as-grown silicon thermal nitride films, the diffusivity and diffusion length of the oxidant species in the as-grown silicon thermal nitride films are deduced. It has been shown that the diffusivity of the oxidant species in the as-grown silicon thermal nitride films is much smaller than that of the oxidant species in the as-grown silicon dioxide and the diffusion length of the oxidant species in the asgrown silicon thermal nitride films is smaller than 12A for dry 02 oxidation below I154~ |
| Databáze: | OpenAIRE |
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