Effects of Pre‐annealing on Firing Stability of Atomic Layer‐Deposited Al2O3. Issue 10 (10th June 2015)

• Record Type: Journal Article
• Authors: Bae, Soohyun; Kim, Soo Min; Lee, Kyung Dong; Kim, Young Do; Park, Sungeun; Kang, Yoonmook; Lee, Hae‐Seok; Kim, Donghwan
• Is Part Of: Israel journal of chemistry. Volume 55:Issue 10(2015)
• Page Start: 1075
• Page End: 1080
• Publication Date: 2015-06-10
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1002/ijch.201400192
• Languages: English
• ISSNs: 0021-2148

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Al<sub>2</sub>O<sub>3</sub> layers fabricated with atomic layer deposition (ALD) show high levels of surface passivation on p‐ and n‐type silicon wafers. In order to form front and rear electrodes, Al<sub>2</sub>O<sub>3</sub> layers should undergo a firing process at a high peak temperature. Therefore, the Al<sub>2</sub>O<sub>3</sub> layer must be stable under these conditions to maintain a high level of surface passivation during the firing process. In this study, Al<sub>2</sub>O<sub>3</sub> layers fabricated with ALD were pre‐annealed to enhance their thermal stability during the firing process. From quasi‐steady state photoconductance (QSSPC) measurements, the difference between the implied <italic>V<sub>oc</sub></italic> values of the pre‐annealed and fired samples was found to be smallest (3 mV) when the sample was pre‐annealed at 620 °C. The surface recombination rate calculated from capacitance‐voltage (<italic>C</italic>‐<italic>V</italic>) measurements of metal‐Al<sub>2</sub>O<sub>3</sub>‐Si (metal‐insulator‐semiconductor) structures was shown to be low when the sample was pre‐annealed at 600–650 °C. Thus, firing stability was achieved with pre‐annealing at 620 °C by reducing the surface recombination rate. We conclude that it is necessary to pre‐anneal the Al<sub>2</sub>O<sub>3</sub> passivation layer at this specific temperature to reduce the degradation of the passivation quality of Al<sub>2</sub>O<sub>3</sub> after the firing process.</p> </abstract>