气压对离子源增强磁控溅射制备氮化铝薄膜的影响

目的 制备性能优异的氮化铝薄膜.方法 采用射频感应耦合离子源辅助直流磁控溅射的方法 制备氮化铝薄膜,在不同的气压下,在Si(100)基片和普通玻璃上生长了不同晶面取向的氮化铝薄膜.使用X射线衍射仪(XRD)、场发射扫描电镜(FESEM)、原子力显微镜(AFM)分析氮化铝薄膜的结构、晶面取向、表面形貌及薄膜表面粗糙度,使用紫外可见分光光度计测定薄膜的透过率,并计算薄膜的禁带宽度.研究气压的大小对磁控溅射制备氮化铝薄膜微观结构的影响.结果 在各气压下,薄膜生长以(100)面取向为主.在0.7Pa前,(100)面的衍射峰强度逐渐增强,0.7 Pa之后减弱.(002)面衍射峰强度在0.6Pa之前较大,0.6Pa之后变小.各气压下薄膜表面均方根粗糙度均小于3nm,且随着气压的增大先增大后减小,0.7 Pa时最大达到2.678nm.各气压下所制备薄膜的透过率均大于60%,0.7Pa时薄膜的禁带宽度为5.4eV.结论 较高气压有利于(100)晶面的生长,较低气压有利于(002)晶面的生长;(100)面衍射峰强度在0.7 Pa时达到最大;随气压的增大,薄膜表面粗糙度先增大后减小;所制备的薄膜为直接带隙半导体薄膜.

Effects of Pressure on Aluminum Nitride Thin Films Deposited by Ion Source Assisted Magnetron Sputtering

Objective To prepare aluminum nitride thin films with excellent performance. Methods Aluminum nitride thin films were deposited by RF inductively coupled plasma ion source enhanced DC magnetron sputtering technique, different orientations of aluminum nitride thin films were deposited on Si(100) and glass by changing the pressure. The crystal structure, orientation, surface morphology and surface roughness of the aluminum nitride thin films were investigated by X-ray diffraction, SEM and AFM, respectively. UV-spectrophotometer was used to measure the transmittance of aluminum nitride thin film, and the optical band gap of aluminum nitride thin film was calculated. The effect of pressure on the microstructure of aluminum nitride thin films deposited by magnetron sputtering was investigated. Results The aluminum nitride thin films were mainly textured along (100) direction under different pressures. The intensity of (100) plane diffraction peak became stronger when the pressure increased to 0. 7 Pa, then became weaker when the pressure exceeded 0. 7 Pa, and the intensity of (002) plane diffraction peak was stronger when the pressure was below 0. 6 Pa than that at higher than 0. 6 Pa. The RMS roughness values of AlN films deposited at various total gas pressure were below 3 nm and the roughness first increased and then decreased with the increase of gas pressure. The RMS roughness values reached 2. 678 nm at the pressure of 0. 7 Pa. The optical transmittance of AlN film at various total gas pressures was all above 60% . The thin film optical band gap was 5. 4 eV at the pressure of 0. 7 Pa. Conclusion The results showed that high pressure was beneficial to the growth of (100) crystal plane, while low pressure was beneficial to the growth of (002) crystal plane. The intensity of (100) plane diffraction peak reached the maximum at 0. 7 Pa. Along with the increase of gas pressure, the surface roughness increased first and then decreased. The films were direct band gap semiconductor films.