Zirconium nitride polycrystalline films grown on Si (111) substrates by metal organic chemical vapor deposition Joo Jin a , Kang Bok Ko a , Hyoun suk Song a , Tran Viet Cuong a,b , Chang-Hee Hong a,n a Semiconductor Physics Research Center, School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju 561-756, South Korea b Department of Solid State Physics, Faculty of Physics, Ho Chi Minh University of Natural Sciences, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam article info Article history: Received 25 January 2014 Accepted 20 March 2014 Available online 26 March 2014 Keywords: ZrN TEMAZr MOCVD X-ray diffraction X-ray photo-electron spectroscopy abstract Metal organic chemical vapor deposition growth of Zr x N y (111) films on silicon (111) substrate was presented with the help of a new metal organic Zr precursor. The effect of growth temperature on the film thickness, surface morphology and stoichiometry was systematically studied. The film thickness and surface roughness were found to reduce with increasing growth temperature. There is a phase transition from Zr 3 N 4 to ZrN when the growth temperature was increased above 950 1C. Consequently, an optimum growth temperature for the monoclinic phase ZrN (111) film on Si (111) substrate was found to be 1050 1C. & 2014 Elsevier B.V. All rights reserved. 1. Introduction ZrN is a golden-yellow colored material with low resistivity, high hardness, and excellent chemical and thermal stability. ZrN films have, therefore, been considered as good candidates for diffusion barrier materials for microelectronics applications [1]. Several methods to grow ZrN thin film had been reported such as physical vapor deposition (PVD) [2], chemical vapor deposition (CVD) [3], and ultrahigh‐vacuum reactive direct current (dc) magnetron reactive sputtering. However, ZrN films grown by using sputtering usually showed multi-crystalline phases such as Zr x N y or Zr x N y O z [2]. Conventional PVD faced poor step coverage in deep contacts and via trenches, owing to a shadowing effect. Many research groups have introduced the potential application of CVD to grow high quality ZrN thin films. Although CVD has many advantages such as excellent thickness uniformity over a large substrate area, low impurity content, and precise thickness control over other deposition methods, the narrow process window and low throughput along with relatively low film density were major obstacles of the CVD system. To overcome these problems, metal– organic CVD (MOCVD) has been investigated as an alternative technique, which is expected to increase the reactivity, reduce the impurity content, widen the process window, and increase the film density [4]. Especially, MOCVD systems possess high tem- peratures for thin film deposition. It has been generally recognized that significantly high substrate temperatures of approximately 750–1100 1C are able to reach [5]. Substrate temperature has a strong effect on structural, stoichiometry, and morphological characteristics of the films. However, MOCVD growth ZrN is still limited mainly owing to the unavailability of the suitable Zr precursors. In this work, the ZrN was grown on Si (111) substrate by using MOCVD system by employing Tetrakis (N,N ethylmethy- lamino) Zirconium (TEMAZr) precursor. In addition, the effect of growth temperature on thickness, structural, stoichiometry, and morphological properties were systematically investigated. 2. Experimental The Si substrates were immersed in a buffered oxide etch solution (BOE; NH 4 F: HF ¼ 6:1) for 10 min to remove the oxide- layer. The substrates were then sonicated in a solution of acetone and methanol for 5 min. Subsequently, the substrates were rinsed with de-ionized water, blown dried with ultrapure nitrogen and loaded into the growth chamber. The growth of ZrN thin films was carried out in a gallium nitride (GaN) MOCVD system equipped with a vertical showerhead (Phaethon 100 series: 6 pocket  2 in. MOCVD) from Topengnet Co., Ltd, Korea. Herein, TEMAZr precur- sor purchased from UP Chemicals Co., Ltd, Korea was applied as Zr precursor because other Zr precursors contain oxygen and can create trouble with hydrogen in MOCVD chamber other than forming Zr x O y . The TEMAZr source was kept in a bath at 75 1C. Except ZTTB, the TEMAZr source has the highest vapor pressure of all the Zr precursors [6], which can ensure a high growth rate. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/matlet Materials Letters http://dx.doi.org/10.1016/j.matlet.2014.03.112 0167-577X/& 2014 Elsevier B.V. All rights reserved. n Corresponding author. Tel.: þ82 63 270 2831; fax: þ82 63 270 3585. E-mail address: chhong@jbnu.ac.kr (C.-H. Hong). Materials Letters 125 (2014) 8–11