Variable temperature LOCOS process
OwnerKelly T. Hurleyinventor
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Abstract
A process of forming isolation structures in semiconductor substrates comprises exposing a selected region of the substrate to an oxidizing ambient held at a first predetermined temperature. As the temperature of the oxidizing ambient is ramped up towards a second predetermined temperature, a relative equilibrium state between oxidation rate and the oxide viscosity is maintained. The process of the present embodiment advantageously is maintained through, the remainder of the equilibrium state oxidation process, so that an isolation layer can be grown without exerting defect-inducing stress over the silicon substrate.
Claims26
A process of forming an isolation region in a semiconductor substrate, comprising:
- providing the substrate with a defined isolation region therein;
- positioning the substrate in a reaction chamber;
- heating the substrate from a first temperature to a second temperature;
- and
- exposing the isolation region to a wet oxidizing ambient while heating the substrate from the first temperature to the second temperature, thereby growing an oxide within the isolation region while heating the substrate.
A process of forming an integrated circuit, comprising:
- defining an isolation region in a semiconductor substrate;
- ramping the temperature of the substrate from a first temperature to a second temperature within a reaction chamber;
- and
- introducing a wet oxidizing gas into the chamber to grow an oxide in the isolation region while ramping the temperature.
A method of forming field isolation elements in a semiconductor substrate, comprising:
- masking a portion of the substrate, leaving an exposed isolation region;
- growing an initial oxide in the exposed isolation region while ramping a substrate temperature from a first temperature to a higher second temperature under a first set of oxidation conditions including at least a segment of wet oxidation;
- and
- after growing the initial oxide, growing a further oxide through the initial oxide while maintaining the substrate at substantially the second temperature.
Dependencies are inferred from the claim text.