Investigation of Plasma Deposition Mechanisms for Silicon Dioxide and Silicon Nitride Films

在这项由化学系先进材料化学计划资助的教师早期职业发展奖中，科罗拉多州立大学的Ellen R.Fisher将研究等离子体增强化学气相沉积二氧化硅薄膜和氢化非晶氮化硅薄膜(α-SiNx：H)。利用一种结合空间分辨激光诱导荧光(LIF)检测和分子束技术的改进的IRIS(自由基与表面相互作用成像)方法，研究气相自由基物种与被射频等离子体处理的表面之间的临界反应。在薄膜沉积过程中，将实时测量自由基的反应性。IRIS将使人们能够研究从表面解吸但不在入射分子束中的自由基，从而获得关于表面反应产生的挥发性产物的信息。将研究烷氧基硅烷等离子体系统以及SiX4/NH3和SiX4/N2等离子体。中间体的反应性将作为射频输入功率、自由基旋转态和衬底温度的函数来测量。二氧化硅和氮化硅薄膜被广泛用作集成电路的栅氧化物、钝化层和层间介质。由于等离子体沉积这些薄膜的机制尚不清楚，通过了解涉及的基本化学过程，如本项目中所提供的，将进一步促进提高薄膜质量的进展。

In this Faculty Early Career Development Award funded by the Advanced Materials Chemistry Program in the Chemistry Division, Ellen R. Fisher of Colorado State University will investigate plasma-enhanced chemical vapor deposition of thin films of silicon dioxide and hydrogenated amorphous silicon nitride films (alpha-SiNx:H). Critical reactions between gas-phase radical species and the surface being processed by an rf plasma will be studied using a modified IRIS (Imaging of Radicals Interacting with Surfaces) method which combines spatially-resolved laser-induced fluorescence (LIF) detection with molecular beam techniques. Radical reactivities will be measured in real time during thin film deposition. IRIS will enable radicals to be studied which desorb from a surface but are not in the incident molecular beam, yielding information about volatile products produced by surface reactions. Alkoxysilane plasma systems as well as SiX4/NH3 and SiX4/N2 plasmas will be examined. The reactivity of intermediates will be measured as a function of rf input power, radical rotational state, and substrate temperature. Silicon dioxide and silicon nitride films are widely used as gate oxides, passivation layers, and interlevel dielectrics for integrated circuits. Since the mechanisms for plasma deposition of these films is still unknown, further progress to improve film quality will be enhanced by understanding the underlying chemical processes involved, such as provided in this project.