Defects in Oxidized p‐Type Si Wafers Observed by Surface Photovoltage Spectroscopy. Issue 17 (8th July 2019)

• Record Type: Journal Article
• Authors: Kolkovsky, Vladimir
• Other Names: Kissinger Gudrun guestEditor.; Kot Dawid guestEditor.; Richter Hans guestEditor.; Zöllner Marvin guestEditor.
• Is Part Of: Physica status solidi. Volume 216:Issue 17(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-07-08
• Subjects: defects -- diffusion length -- oxygen -- silicon -- surface photovoltage spectroscopy; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201900310
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Surface photovoltage spectroscopy (SPV) is widely used for semiconductor characterization in modern microelectronics. Herein, the results of a comprehensive SPV analysis of oxidized n‐ and p‐type Czochralski (Cz) Si wafers with an oxygen concentration of about 5–7 × 10 17 cm −3 are reported. It is demonstrated that the oxidation of the wafers with different H2 /O2 ratios can significantly influence the diffusion length of minority carriers in p‐type Si. This effect is explained by the formation of oxygen–hydrogen‐related defects which are strong recombination centers in such wafers. In addition, a significant degradation of the diffusion length of minority carriers is observed in oxidized p‐type Si wafers after annealing at 90 °C and a subsequent illumination at room temperature. This degradation is found to be independent of oxide growth conditions, and it is not observed in n‐type wafers. This degradation is correlated with the presence of low concentrations of interstitial Fe (<10 11 cm −3 ) in some wafers and with boron–oxygen‐related defects in some other wafers. Abstract : Oxidation processes under different conditions can lead to the formation of electrically active defects in silicon wafers. A significant degradation of minority carrier diffusion length is observed in wet oxidized p‐type silicon wafers by using the surface photovoltage technique. Such a degradation is not detected in wet oxidized n‐type silicon wafers. Different models are suggested to explain this degradation.