Thermal Conductivity of Nano-Crystallized Indium-Gallium-Zinc Oxide Thin Films Determined by Differential Three-Omega Method

Abstract

The temperature dependence thermal conductivity of the indium-gallium-zinc oxide (IGZO) thin films was investigated with the differential three-omega method for the clear demonstration of nanocrystallinity. The thin films were deposited on an alumina (α-Al2O3) substrate by direct current (DC) magnetron sputtering at different oxygen partial pressures ([PO2] = 0%, 10%, and 65%). Their thermal conductivities at room temperature were measured to be 1.65, 1.76, and 2.58 Wm−1K−1, respectively. The thermal conductivities decreased with an increase in the ambient measurement temperature. This thermal property is similar to that of crystalline materials. Electron microscopy observations revealed the presence of nanocrystals embedded in the amorphous matrix of the IGZO films. The typical size of the nanocrystals was approximately 2–5 nm with the lattice distance of about 0.24–0.26 nm. These experimental results indicate that the nanocrystalline microstructure controls the heat conduction in the IGZO films.

Influence of NF3 Plasma-Treated HfO2 Gate Insulator Surface on Tin Oxide Thin-Film Transistors

“…Also, polycrystalline SnO 2 demonstrated a thermal conductivity between 25 and 40 W/(Km) [60]. As a comparison, IGZO demonstrates a thermal conductivity of ~1-8 W/(Km) in both an amorphous and crystalline state (i.e., CAAC-IGZO) [61][62][63]. The porosity and also the fabrication process of the material are important parameters in the thermal conductivity values [63].…”

Indium-free GZO thin films prepared using plasma-enhanced atomic layer deposition: toward thin film transistor application

“…[1][2][3][4][5][6][7][8] Indium-gallium-zinc oxide (IGZO) is considered one of the most promising channel layer materials to meet the requirements of TFTs. [9][10][11][12][13][14][15][16][17][18][19][20] Unfortunately, indium is toxic and scarce, limiting its commercial application and making the device environmentally unfriendly and costly. 21,22 Moreover, it has been found that chemical composition has a considerable impact on the performance of IGZO TFTs, 23 and it is difficult to accurately control the composition of IGZO containing four components.…”

Back-Channel Etched In-Ga-Zn-O Thin-Film Transistor Utilizing Selective Wet-Etching of Copper Source and Drain

“…Recently, IGZO TFTs are used as a switching device in flat panel displays, such as active-matrix organic light-emitting diode (AMOLED) displays, active-matrix liquid crystal displays (AMOLCD) and electrophoretic displays [4,5]. Most of the studies are focused on the electrical, electronic, optical and thermal properties of IGZO thin films [6,7]. There are also several studies to improve these parameters for the transistors by using Dirac materials, with the tunneling and trapping effects as the main approach [8,9].…”