Formation of black silicon using SiGe self-assembled islands as a mask for selective anisotropic etching of silicon. (1st March 2018)

• Record Type: Journal Article
• Authors: Yurasov, D.V.; Novikov, A.V.; Shaleev, M.V.; Baidakova, N.A.; Morozova, E.E.; Skorokhodov, E.V.; Ota, Y.; Hombe, A.; Kurokawa, Y.; Usami, N.
• Is Part Of: Materials science in semiconductor processing. Volume 75(2018)
• Page Start: 143
• Page End: 148
• Publication Date: 2018-03-01
• Subjects: Black silicon -- SiGe islands -- Selective wet etching -- Weighted reflection -- C-Si solar cells; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2017.11.032
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Simple technique of formation of "black silicon" using wet chemical etching of crystalline Si wafers with SiGe self-assembled islands is proposed. The main idea consists of the utilization of SiGe islands as a mask for wet anisotropic etching of Si in alkali-based solution at the first etching stage and further removal of SiGe residuals by etching in a HF:H2 O2 :CH3 COOH mixture at the second etching stage. Initial samples were the crystalline Si wafers with SiGe islands formed on them by deposition of 2.5–14 nm of Ge at 800 °C. After the two above-mentioned etching steps a submicron relief on a Si surface was formed. Investigation of optical properties of fabricated structures revealed significant decrease of reflection (AM 1.5 G weighted reflection ~2–3%) and increase of absorption in the wavelength range of 500–1200 nm. Due to the very small amount of Si removal (<0.5 µm), utilization of standard chemicals for Si-based solar cell technology and potential suitability for usage in large-scale manufacturing the proposed technique is promising for increasing of efficiency of thin wafers crystalline Si solar cell.