SnO 2 thin films grown by atomic layer deposition using a novel Sn precursor

• DOI: 10.1016/j.apsusc.2014.09.054
• Publication Date: 2014-09-21T20:47:33Z
• Authors: Min-Jung Choi; Cheol Jin Cho; Kwang-Chon Kim; Jung Joon Pyeon; Hyung-Ho Park; Hyo-Suk Kim; Jeong Hwan Han; Chang Gyoun Kim; Taek-Mo Chung; Tae Joo Park; Beomjin Kwon; Doo Seok Jeong; Seung-Hyub Baek; Chong-Yun Kang; Jin-Sang Kim; Seong Keun Kim
• Keywords: Auger electron spectroscopy; Carbon fibers; Amorphous carbon; Atmospheric temperature range

Abstract SnO 2 thin films were grown by atomic layer deposition (ALD) with dimethylamino-2-methyl-2-propoxy-tin(II) (Sn(dmamp) 2 ) and O 3 in a temperature range of 100–230 °C. The ALD window was found to be in the range of 100–200 °C. The growth per cycle of the films in the ALD window increased with temperature in the range from 0.018 to 0.042 nm/cycle. Above 230 °C, the self-limiting behavior which is a unique characteristic of ALD, was not observed in the growth because of the thermal decomposition of the Sn(dmamp) 2 precursor. The SnO 2 films were amorphous in the ALD window and exhibited quite a smooth surface. Sn ions in all films had a single binding state corresponding to Sn 4+ in SnO 2 . The concentration of carbon and nitrogen in the all SnO 2 films was below the detection limit of the auger electron spectroscopy technique and a very small amount of carbon, nitrogen, and hydrogen was detected by secondary ions mass spectroscopy only. The impurity contents decreased with increasing the growth temperature. This is consistent with the increase in the density of the SnO 2 films with respect to the growth temperature. The ALD process with Sn(dmamp) 2 and O 3 shows excellent conformality on a hole structure with an aspect ratio of ∼9. This demonstrates that the ALD process with Sn(dmamp) 2 and O 3 is promising for growth of robust and highly pure SnO 2 films.