Paper
27 August 1999 Analysis of phosphorous autodoping in P-type silicon measured using corona oxide silicon (COS) techniques
Brian Letherer, Gregory Horner
Author Affiliations +
Abstract
Semiconductor fabrication facilities rely on the integrity of the silicon to manufacture sub-micron devices. Cross contamination of P-type silicon to N-type carriers or vice versa in the near surface region of the silicon can be detrimental to device performance. Semiconductor processing typically includes numerous diffusion and pre-clean steps, any one of which might auto-dope P-type silicon substrate with phosphorous. Inline monitoring of these near surface doping effects enhances the ability to diagnose autodoping problems. A non-contact Corona Oxide Silicon (COS) measurement technique has the ability to detect cross-contaminated P-type silicon with phosphorous from wet clean benches and diffusion furnaces. Results show COS flatband (Vfb) and oxide total charge (Qtot) measurements are sensitive to various levels of intentional phosphorous contamination implanted into the silicon at pre-oxidation. Phosphorous at the silicon/oxide interface can pile up and create an electrically active thin 'N' skin. Phosphorous from this thin 'N' skin is shown to change the electrical characteristics of near surface region of the silicon. The detection of unwanted phosphorus with the use of COS inline monitoring can greatly reduce the response time when auto-doping problems occur.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Brian Letherer and Gregory Horner "Analysis of phosphorous autodoping in P-type silicon measured using corona oxide silicon (COS) techniques", Proc. SPIE 3884, In-Line Methods and Monitors for Process and Yield Improvement, (27 August 1999); https://doi.org/10.1117/12.361333
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KEYWORDS
Silicon

Oxides

Contamination

Semiconducting wafers

Doping

Diffusion

Interfaces

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