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the wet etch rate increases as the silanol concentration increases.The residual stress is highly dependent upon the substrate temperature. Upon cooling~ the residual stress becomes more compressive because the thermal-expansion of silicon dioxide is less than that of silicon. Because the films deposited at higher temperature are cooled over a greater temperature range, they exhibit a larger compressive stress at room temperature. Increasing the RF power or decreasing the reactor pressure enhances the ion bombardment effect which causes the residual stress to become more compressive.Although the substrate temperature causes the most significant decrease in impurity concentration, the deposition temperature must be limited if the oxide is to be used in metal-insulator structures. Using a large RF power, high pressure, and low nitrous oxide to silane ratio will minimize the silanol concentration at a given temperature. This, in turn, will minimize the dielectric constant and maximize the etch and solvent resistance of the oxide produced. ABSTRACTThe influence of rapid thermal annealing, thermal donor formation, and hydrogen on the precipitation of oxygen was studied by infrared analyses. We concluded that the oxygen loss during the subsequent precipitation steps is not directly correlated with the quantity of thermal donors formed. Our study supports rather that thermal donors are made of self-interstitial agglomerates. However, a 450~ treatment and a prior rapid thermal annealing enhances the precipitation of oxygen, through a path which does not lead to platelets. Indeed spherical precipitates evidenced by infrared analyses are formed early at low temperature, during the thermal treatment at 750~ They may grow from aggregates, formed at 450~ and we think that they are made of oxygen atoms and vacancies. The growth of these aggregates occurs as the temperature of the thermal treatments increases and is enhanced by a prior rapid thermal anneal. Finally, a retardation of the precipitation due to hydrogen introduced during a pretreatment was observed in specific conditions. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.49.23.145 Downloaded on 2015-03-16 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.49.23.145 Downloaded on 2015-03-16 to IP

The influence of classic and rapid thermal annealing pretreatments under nitrogen or hydrogenated ambients on thermal donor formation and on the further oxygen nucleation step were studied. A rapid thermal annealing at 1200~ under a nitrogen ambient delayed the formation of thermal donors. If nitrogen was replaced by a hydrogenated ambient, thermal donor formation was largely enhanced. In each case further nucleation was affected. A modification of the precipitation path due to rapid thermal annealing is proposed to be at the origin of the tremendous effect of a prior lamp anneal on the internal gettering process. The classic heterogeneous nucleation of the platelets would be prevented and the precipitation would proceed through a homogeneous path leading to precipitates unable to getter metal impurities.

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