溅射温度对Ga_(2)O_(3)薄膜物理特性的影响

Effect of Sputtering Temperature on Physical Properties of Ga_(2)O_(3) Thin Films

采用射频磁控溅射法在蓝宝石(Al_(2)O_(3))衬底上制备Ga_(2)O_(3)薄膜,研究溅射温度对Ga_(2)O_(3)薄膜晶体结构、表面形貌、光学特性的影响。X射线衍射结果显示,温度过低不利于薄膜晶化,随着温度的升高,结晶质量变好;通过计算薄膜晶体的粒径、晶面间距、非均匀应变和织构系数,发现四组样品均沿(201)晶面择优生长,450℃时所制备的Ga_(2)O_(3)薄膜结晶质量最好。扫描电子显微镜(SEM)结果表明,随着温度的升高,Ga_(2)O_(3)薄膜粒径逐渐增大,结晶质量变好。光学吸收谱图表明,随着温度的升高,Ga_(2)O_(3)薄膜禁带宽度先增大后减小,平均值为4.88 eV。透射谱图表明,Ga_(2)O_(3)薄膜在可见光波段的平均透过率约为85%,适合作为高信噪比紫外探测器的吸收层。该项研究为Ga_(2)O_(3)在紫外探测及高功率电子器件领域的应用提供了参考。

Ga_(2)O_(3)thin films were prepared on sapphire (Al_(2)O_(3)) by RF magnetron sputtering.The effects of sputtering temperature on the crystal structure,surface morphology and optical properties of Ga_(2)O_(3)thin films were studied.X-ray diffraction results show that too low temperature is not conducive to film crystallization,and with the increase of temperature,the crystal quality becomes better.By calculating grain size,crystal plane spacing,non-uniform strain and the texture coefficient of the film crystal,it is found that the four groups of samples grow preferentially along the (201) crystal plane,and the Ga_(2)O_(3)thin film prepared at 450℃has the best crystal quality.Scanning electron microscopy (SEM)results show that the grain size of Ga_(2)O_(3)thin films increases and crystallization quality becomes better with the increase of temperature.The optical absorption spectra show that the band gap energy of the Ga_(2)O_(3)thin film increases first and then decreases with the increase of temperature,and the average value is 4.88 eV.The transmission spectra show that the average transmittance of the Ga_(2)O_(3)thin film in visible light band is about 85%,so it is suitable as the absorption layer of ultraviolet detector with high signal-to-noise ratio.This study provides a reference for the application of Ga_(2)O_(3)in ultraviolet detection and high power electronic devices.