Static and low-frequency noise characteristics of n+p junction diodes fabricated in different silicon substrates

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Abstract
This paper describes the impact of the starting Si material and thermal pretreatment on the static current-voltage characteristics of n+p junction diodes, using a combination of large-area, large-perimeter and gated diodes. In addition, the low-frequency noise spectrum in forward operation is studied for different p-type substrates. It is shown that in Czochralski-grown (Cz) wafers, the starting oxygen concentration plays a crucial role: highly precipitated high-oxygen diodes show a large bulk and perimeter leakage current and a high ideality factor m. Near ideal behaviour (m approximately=1) is found for epitaxial and floating-zone (FZ) grown substrates. The surface generation/recombination properties, however, are marginally affected by the interstitial oxygen content. Simultaneously, a clear impact of the substrate type on the low-frequency noise is observed, especially for high forward currents, whereby the lowest noise figures are obtained for epitaxial and FZ wafers. It is demonstrated that in Cz wafers both perimeter (surface) and bulk noise sources are active, explaining the higher noise level.