本實驗探討的結構是在SiO2線上鍍以固定厚度的鈦和不同厚度的氮化鈦,然後以臨場曲率量測系統得到線狀結構應力隨溫度變化的行為。由應力-溫度曲線可得知結構所表現出最主要的趨勢是由佔有大部分比例的SiO2導致,但鍍在其上的鈦和氮化鈦隨著溫度升高而造成的影響也會表現在曲線上,如鈦吸氧所引起的壓應力和氮化鈦應力疏散使整體應力往張應力方向變化,而這些效應對曲線所造成的影響也會與線寬效應有關,線狀結構的側壁會把對應力的影響疏散掉,當結構有較大線寬時,側壁的數量較少,在曲線上所引起的改變也會較大,而側壁的數量在垂直線方向隨線寬變化較平行線方向來得敏感,所以應力的改變在較小線寬的垂直線方向上可能會看不到。以有限元素分析法模擬結構的應力可輔助解釋實驗上看到的現象,當鈦和氮化鈦越厚時,結構有越小的熱應力,這是因為鈦和氮化鈦的熱膨脹係數較大,可彌補SiO2和矽基版間熱膨脹係數的差異,此項效應隨著線寬越大而越顯著,因為被線狀結構側壁疏散掉的影響越少。透過模擬矽化物形成時,結構中體積的改變情況,可推論曲線在高溫時有一突然往張應力方向的變化是由於反應時體積改變所引起的,但由於應力隨線寬變化的行為與實驗上所觀察到的不符合,因此模擬反應所造成的應力變化還需要更精確的假設。模擬矽化物在結構中的應力以及實驗上退火後的XRD結果和曲線,可得知矽化物的形成使結構的應力較反應前的結構小,在較大的線寬結構時差別會越大,可能是C54-TiSi2的反應越完全所導致。
The stress behaviors of the periodic lines structure with Ti and TiN deposited on SiO2 lines has been investigated by in-situ curvature measurement system. The stress-temperature curves are dominated by the SiO2 lines which are the primary parts in the whole structures, and the curves also present the influences of Ti and TiN, like the compressive stresses from oxygen-absorbing of Ti layers and the change toward tensile stress by stress relaxation in TiN layers. The effects from Ti and TiN are dependent on the linewidth of the structures because the vertical side walls can relax the stresses. The changes of the stresses due to Ti and TiN are larger in structures with larger linewidth because the number of side walls is fewer when the linewidth of the structure is larger. The structures with thicker TiN have smaller thermal stress due to its higher coefficient of thermal expansion decrease the differences between the line-like SiO2 layer and the substrate.