Effect of sputtering time on physical and electrical properties of ZrO<DN>x</DN> thin film on Si
Authors: Tedi, K.; Cheong, K.Y.; Lockman, Z.
Source: Microelectronics International, Volume 28, Number 3, 2011 , pp. 7-11(5)
Publisher: Emerald Group Publishing Limited
Abstract:<B>Purpose</B> - The purpose of this paper is to report the effect of sputtering time on the electrical and physical properties of ZrO<DN>x</DN>. ZrO<DN>x</DN> (measured thickness is ranging from 20.5 to 51.3?nm) thin films as gate oxide materials are formed by metal deposition at different sputtering time and thermal oxidation techniques. <B>Design/methodology/approach</B> - Zirconium is deposited on silicon substrate at three different sputtering time; 30-, 60- and 120-s continued with an oxidation process conducted at 500°C for 15?min to form ZrO<DN>x</DN> thin films. High-resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy and electrical characterizations were used to examine the properties of the thin film. <B>Findings</B> - A broad ZrO<DN>x</DN> peak lies in between 26° and 31° from HR-XRD is presumed as the effect of small thickness of ZrO<DN>x</DN> and or the ZrO<DN>x</DN> is still partially crystalline. FTIR spectroscopy results suggested that besides ZrO<DN>x</DN>, SiO<DN>x</DN> interfacial layer (IL) has also formed in all of the investigated samples. As the sputtering time increases, hysteresis between the forward and reverse bias of capacitance-voltage curve has reduced. The lowest leakage current density and the highest oxide breakdown voltage have been demonstrated by 60-s sputtered sample. These may be attributed to a lower effective oxide charge and interface trap density. The extracted dielectric constant (?) of these oxides is ranging from 9.4 to 18, in which the ? value increases with the increase in sputtering time. <B>Originality/value</B> - ZrO<DN>x</DN> thin film which was fabricated by sputtering method at different sputtering time and thermal oxidation techniques showed distinctive electrical results. SiO<DN>x</DN> IL formed in the samples.
Document Type: Research article
Publication date: 2011-08-02