Fabrication of a silicon-silicon dioxide interface of predetermined space charge polarity
Abstract
Abstract IN THE FABRICATION OF A SEMICONDUCTOR DEVICE HAVING A SILICON-SILICON DIOXIDE INTERFACE, THE POLARITY OF THE SPACE CHARGE REGION ASSOCIATED WITH THE INTERFACE IS PREDETERMINED BY A METHOD WHICH BEGINS WITH THE STEP OF PRETREATING THE SILICON SURFACE WITH A SELECTED REAGENT CAPABLE OF INDUCING THE DESIRED SPACE CHARGE POLARITY. FOR EXAMPLE, A PRETREATMENT WITH CHROMIC ACID INDUCES A NEGATIVE SPACE CHARGE REGION, WHEREAS A PRETREATMENT WITH NITRIC ACID INDUCES A POSITIVE CHARGE. THE INTERFACE IS THEN FORMED BY VAPOR DEPOSITION OF A SLICON DIOXIDE LAYER ON THE SILICON SURFACE. THE PRETREATMENT HAS BEEN FOUND CAPABLE OF INDUCING A PREDETERMINED CHARGE WHEN THE INTERFACE IS PROVIDED BY VAPOR DEPOSITION, BUT IS WHOLLY INEFFECTIVE WHEN THE INTERFACE IS PROVIDED BY THERMAL OXIDATION. IT IS WELL KNOWN THAT THERMAL OXIDATION OF A SILICON SURFACE INHERENTLY PRODUCES AN INTERFACE HAVING A POSITIVE SPACE CHARGE REGION.
Inventors
- 👤 Frank J Barone
- 👤 Donald L Tolliver
Bibliographic Details
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