本論文主要研究方向為利用氧化物(鈧酸鈥，HoScOx)非晶薄膜作為擴散阻障層以提升銅鍍層在矽上的高溫穩定性質。結果顯示HoScOx(x=3~4)具有高溫穩定性且為非晶薄膜，其結晶溫度高達900℃以上。在Cu/HoScOx/SiO2/Si擴散阻障層研究中，擴散阻障層的厚度估計約為3nm、5nm和10nm (簡稱為阻障層厚度)。最高穩定溫度退火1小時 (即電阻率未明顯上升之溫度)在3nm、5nm及10nm的阻障層厚度下，分別為600℃、700℃和700℃；不過在X-射線繞射光譜儀(XRD)分析結果顯示銅矽化合物早已於較低的溫度生成，實驗中利用不同入射角(glancing angle)的XRD分析，得知了銅矽化合物是由銅擴散至矽基材而產生的，採用較大的入射角時，其偵測到銅矽化合物的訊號溫度為比以電阻率為依據的最高穩定溫度(600℃)稍低。由掃描式電子顯微鏡(SEM)分析發現，銅矽化合物隨著溫度的提高而產生，且在800℃，銅膜表面形成了島嶼狀。HoScOx(3nm)經700℃高溫退火後，穿透式電子顯微鏡(TEM)影像分析結果得知原先明顯的界面已經變模糊且消失，說明了銅矽間已經開始擴散且產生了銅矽化合物。Cu/HoScOx/SiO2/Si多層膜結構在歐傑電子能譜儀(AES)縱深分析的結果中可清楚的觀察到層狀結構會隨退火溫度而變化。在附著力測試研究中，得知非晶薄膜HoScOx有效提升銅與矽之間的附著力。

In this study, sputtered Cu film thermal properties on Si substrate have been improved using an amorphous oxide (HoScOx) as the diffusion barrier layer. For this HoScOx (x=3~4) film only (hereafter called the HoScOx layer), it still possesses good thermal stability and amorphous structure after annealing. This barrier layer has high crystallization temperature of 900℃ and above. For the barrier studies in Cu/HoScOx/SiO2/Si, the maximum stable temperatures where the film resistivity is not changed are 600℃, 700℃ and 700℃ for barrier layers with thicknesses of 3nm, 5nm and 10nm, respectively. However, the copper silicides are formed already at low temperatures as shown in X-ray diffraction (XRD) results. For the different glancing angle XRD experiments, the appearance of Cu3Si peaks is used as an indicator for Cu diffusion into the substrate. Cu3Si peaks are appeared at relatively low temperatures in large glancing angle. In scanning electron microscopy (SEM) results, The Cu3Si is appeared and grown with increasing annealing temperature. After annealing at 800℃, the top of Cu film becomes isolated islands as a result of Cu-Si interactions. In transmission electron microscopy (TEM) results, annealing at 700℃ for 1 hour, the original smooth surface in as-deposited film became rough. It is said that the Cu and Si reacted each other and Cu3Si is formed. For Auger electron nanoscope (AES) results on Cu/HoScOx/SiO2/Si structures, it is clearly seen the multi-layer is changed during annealing temperature at high temperatures. In addition, the adhesion of Cu film on Si is enhanced significantly by placing HoScOx in between.

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