Chistiakova, G.; Mews, M.; Wilks, R.G.; Bär, M.; Korte, L.: In-system photoelectron spectroscopy study of tin oxide layers produced from tetrakis(dimethylamino)tin by plasma enhanced atomic layer deposition. Journal of Vacuum Science & Technology A 36 (2018), p. 02D401/1-6
10.1116/1.5015967
Open Accesn Version

Abstract:
Tin oxide (SnO2) layers were deposited using plasma enhanced atomic layer deposition with tetrakis(dimethylamino)tin precursor and oxygen plasma. The deposited layers were analyzed by spectral ellipsometry, conductivity measurements, and in-system photoelectron spectroscopy. Within a deposition temperature range of 90–210 °C, the resistivity of the SnO2 layers decreases by 5 orders of magnitude with increasing deposition temperature. At the same time, the refractive index at 632.8 nm increases from 1.7 to 1.9. These changes in bulk layer properties are connected to results from photoelectron spectroscopy. It is found that decreasing carbon and nitrogen contaminations in the tin oxide layers lead to decreasing optical band gaps and increasing refractive index. Additionally, for the deposited SnO2 layers, a shoulder in the O 1s core level spectrum is observed that decreases with the deposition temperature and thus is proposed to be related to hydroxyl groups.