氮化鈦薄膜與低介材HSQ應用於銅金屬製程之性質研究

Abstract

氮化鈦薄膜與低介材HSQ應用於 銅金屬製程之性質研究 研究生：鄭淳元 指導教授：龍文安 博士 國立交通大學 應用化學研究所碩士班 摘要 以不同比例之氬與氮為濺鍍氣体，沉積金屬鈦薄膜、不同含量之氮化鈦及鈦/氮化鈦雙層薄膜，另以鈦金屬薄膜在電漿之環境下，通入氮氣進行表面改質。以四點探針、AES、XRD、AFM、SEM、ESCA及應力量測儀分析上述薄膜作為銅擴散阻障層之特性。 在銅/鈦/矽結構中，鈦阻障層厚10奈米，在25℃時，電阻係數為3.8μΩ-cm，於400℃、1小時回火處理後，發現Cu薄膜劣化，Ti阻障層失效，使電阻係數驟升為50.3μΩ-cm。在銅/氮化鈦/矽結構中，700℃回火後，表面有Cu3Si晶體析出。銅/氮化鈦/鈦/矽結構之電阻係數介於銅/氮化鈦/矽結構與銅/鈦/矽結構之間，當N2/Ar流量在6/24 sccm以下時，壓縮應力明顯下降，且其失效溫度可高達700℃。 鈦薄膜經氮電漿改質，發現功率對電阻係數影響最大，有49%η總變異是由功率因子所導致；而時間對表面粗糙度影響最大，有80%η總變異是由時間因子所導致。

The Study on the Properties of TiNx Thin Film and Low-k Material HSQ for Copper Metallization Process Student: Cheng Chun-yuan Advisor: Dr. Loong Wen-an Institute of Applied Chemistry, National Chiao Tung University Abstract The depositions of Ti, TiNx and TiNx/Ti bilayer thin films with various ratios of argon and nitrogen sputtering gases, and the surface modification of Ti thin film by N2 plasma were achieved. By applying 4-point probe, AES, XRD, AFM, SEM, ESCA and stress measurement system to analyze their properties as Cu diffusion barrier layer. In the multi-structure of Cu/Ti/Si, thickness of Ti diffusion barrier is 10 nm, The resistivity of the structure was 3.8 μΩ-cm at 25℃, after 400℃, 1 hour annealing, the surface of Cu thin film was degraded, and Ti barrier breakdown was found , resistivity increased sharply to 50.3 μΩ-cm. In the multi-structure of Cu/TiNx/Si, when the temperature of annealing was brough up to 700℃, crystalline Cu3Si was found on the surface. The resistivity of Cu/TiNx/Ti/Si was found between Cu/TiNx/Si and Cu/Ti/Si, when the N2/Ar flow ratio was below 6/24 sccm, compressive stress decreased apparently, and breakdown temperature increased up to 700℃. In the process of surface modification of Ti thin film by N2 plasma, the results showed that power effects the most to resistivity, there was 49％ η variance caused by factor of power. The time effects the most to surface roughness, there was 80％ η variance caused by factor of time.