- 學位論文
反應濺鍍氮化鋯於 (100)矽晶片之異質磊晶成長與退火之研究
The study of heteroepitaxial ZrN film on Si (100) substrate by reactive sputtering deposition and annealing
摘要
氮化鋯(ZrN)具有立方晶體結構，屬於陶瓷材料，為導電氮化物，擁有高熔點、高硬度等優越性質。除了在半導體產業可以作為Si基板上之緩衝層外，在生醫產業方面也可作為離子保護膜。本研究分兩部分，第一部分利用DC反應式磁控濺鍍系統以純金屬Zr為靶材，通入不同比例超高純度之Ar與N2氣體，以不同功率濺射Zr靶材，使Zr與N2反應成ZrN成長磊晶薄膜於(100)面之Si基板上，找出最佳的濺鍍製程參數；第二部分以微波氮氫電漿高溫退火ZrN磊晶薄膜，分別在不同功率及壓力下其改善磊晶品質之程度。 分析部分利用高解析X光繞射儀(XRD)以2θ-掃描模式分析薄膜晶體結構、X光搖擺曲線(x-ray rocking curve, XRC)之半高寬(full-width at half-maximum, FWHM)分析薄膜品質以及Phi-scan確認薄膜與基板間磊晶關係；以四點探針及霍爾電性分析測量其電阻率；掃描式電子顯微鏡(SEM)以其原子力顯微鏡(AFM)分析薄膜表面形貌；以穿透式電子顯微鏡(TEM)分析薄膜界面、中間以及表面結構。利用X光電子能譜(XPS)分析薄膜縱深組成分布。第一部分反應濺鍍製程分別探討功率、N2比例、與沉積時間等對薄膜品質之影響；第二部分退火製程則變化微波功率，使得退火溫度範圍達到800 C ~ 1050 C。 反應濺鍍沉積基板溫度860 C、功率50 W、N2比例8 %製程1小時可以成長出ZrN(100) 磊晶薄膜， ZrN薄膜(200)XRC之FWHM有最低之值1.36，並得到其磊晶關係為ZrN (200) // Si (100)且ZrN [011] // Si [011]，薄膜電阻率約為49 μΩ·cm。從XRD量測之平面間距及XPS成分分析可知薄膜內部Zr與N之比值接近1。將以TEM觀察薄膜微觀結構，可以看到有因為{111}疊差缺陷堆疊產生之斜向晶粒樣貌。製程時間縮短至30分鐘，ZrN薄膜品質較差，(200)XRC之FWHM為1.8。第二部分利用氮氫電漿退火在大約800C 退火可將ZrN薄膜品質提升，(200)XRC之FWHM從1.36降至0.98；而退火溫度高達1000C 可以更進一步提升ZrN薄膜品質，ZrN (200)XRC之FWHM為0.63，電阻率降至35 μΩ·cm。TEM觀察薄膜內部看出缺陷明顯減少。退火後薄膜內部Zr與N之比值仍接近1，組成並未發生改變。 本研究成功以DC反應式濺鍍沉積ZrN於Si(100)基板上，並利用退火得到高品質之磊晶薄膜品質。
並列摘要
ZrN has rock-salt crystal structure and is a conducting nitride with many excellent properties such as high melting point and high hardness. It can be appropriate buffer layer for growing diamond on Si wafer. This thesis focuses on the study of growth of epitaxial ZrN film on Si. This study is divided into two parts. The first part focuses on ZrN epitaxial film qualities by varying with the reactive sputtering processing conditions especially the sputter power and gas ratio. We use metal Zr as the sputtering target. Ar and N2 were used as processed gas. In the second part, microwave plasma was used to improve the quality of ZrN thin film at different processing conditions by high temperature annealing, and a comparison with sputtered films was also made. The crystallinities of as-sputtered and annealed ZrN thin film were characterized by X-ray diffraction (XRD. The morphologies of thin films were analyzed by atomic force microscopy (AFM) and scanning electron microscope (SEM). Transmission electron microscopy (TEM) was used to to observes the micro-structure and x-ray photoelectron spectroscopy (XPS) was used to to analyze the composition of ZrN thin film at difference depths. In the first part, we fixed the working pressure at 3 10-3 torr and the total gas flow at 25 sccm. We analyzed the effects of power of plasma from 40 W to 60 W and ration of N2 from 7% to 9%. In the second part, we annealed the ZrN films with the best quality grown by sputtering at different microwave powers and pressures. The range of annealing temperature is 800 C to 1050 C. The results show the ZrN film epitaxial grown on Si at substrate temperature of 860C with 8% N2 has the best quality with the lowest full width at half maximum (FWHM) of 1.36 for (002) x-ray rocking curve (XRC). Its resistivity is about to 49 μΩ·cm. Addationally, we reduce the process time to 30 minutes and the XRC FWHM of ZrN (200) is approach to 1.8. The TEM analysis show that there are a lot of defect in the ZrN thin film such as stacking fault. The XPS analysis show that the composition ratio of Zr and N is nearly equal to 1. Furthermore, the XRD and TEM analyses show that the epitaxial relationship between ZrN and Si is ZrN (200) // Si (100) and ZrN [011] // Si [011]. Annealing at 800C, we focus to enhance the quality for ZrN thin film. ZrN (200) XRC FWHM decreases to 0.98. When the annealing temperature is 1000C, ZrN (200) XRC FWHM decreases further to 0.98 and the resistivity reduced to 35 μΩ·cm. It can be obviously seen that we also reduce the defect in the ZrN thin film as revealed by TEM analysis. It also observed that there have formed the ZrO2 on the surface after annealing experiment. The XPS show that the composition ratio of Zr and N is nearly equal to 1 after annealing. In this study, ZrN was successfully grown on a Si (100) substrate by DC reaction. The film with high quality was obtained by annealing.