Effect of balanced and unbalanced magnetron sputtering processes on the properties of SnO2 thin films

• Published in: Current applied physics Vol. 19; no. 6; pp. 697 - 703
• Main Authors: Shanker, Gauri, Prathap, P., Srivatsa, K.M.K., Singh, Preetam
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-06-2019; 한국물리학회
• Subjects: Electrical properties; Photoluminescence; SnO2 thin film; Spectroscopic ellipsometer; Unbalanced magnetron sputtering; 물리학; SnO2 thin film; Electrical properties; Unbalanced magnetron sputtering; Spectroscopic ellipsometer; Photoluminescence
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2019.03.016

A comparative study has been carried on the role of balanced magnetron (BM) and unbalanced magnetron (UBM) sputtering processes on the properties of SnO2 thin films. The oxygen partial pressure, substrate temperature and deposition pressure were kept 20%, 700 °C and 30 mTorr, respectively and the applied RF power varied in the range of 150–250 W. It is observed that the UBM deposition causes significant effect on the structural, electrical and optical properties of SnO2 thin films than BM as evidenced by X-ray diffraction, C-V, Spectroscopic Ellipsometer and Photoluminescence measurements. The value of band gap (Eg) of the films deposited at 150 W in UBM is found as Eg = 3.83 eV which is much higher than the value of Eg = 3.69 eV as observed in BM sputtering indicating that UBM sputtering results in good crystalline quality. Further, the C-V measurements of SnO2 thin films deposited using UBM at high power 250 W show hysteresis with large flat band shift indicating that these thin films can be used for the fabrication of memory device. The observed results have been attributed to different mechanisms which exist simultaneously under unbalanced magnetron sputtering due to ion bombardment of growing SnO2 thin film by energetic Ar+ ions.
•Properties of SnO2 films were investigated under BM and UBM sputtering processes.•UBM sputtering process enables to deposit films with high crystallinity than BM.•C-V curve of SnO2 film under UBM sputtering at 250 W showed large flat band shift.•SnO2 films using UBM sputtering can be used for the fabrication of memory device.