过渡层ZrO_2对不同沉积厚度TiO_2薄膜结构的影响

Effect of ZrO_2 Buffer Layer on the Structures of TiO_2 Films with Various Deposition Thicknesses

TiO2作为高介电常数材料已被广泛研究。为了防止TiO2与Si基底发生反应,在Si与TiO2之间加入与TiO2结构相似热稳定性好的ZrO2作为过渡层。改变TiO2薄膜厚度,并在900℃对薄膜进行1h退火处理。通过XRD分析显示,随着TiO2厚度减小,各衍射峰强度逐渐降低,但各峰位及其相对强度无明显变化。通过SEM可以发现,热处理前各薄膜均无裂纹和孔洞。热处理后,TiO2厚度为150nm及80nm的薄膜平整光滑无裂纹孔洞,晶粒排列致密晶界清晰,当TiO2厚度降为30nm时,薄膜仍平整光滑,只在晶界上出现因热处理而产生的缩孔。

TiO2 has been studied as a high-K material extensively. When TiO2 is directly deposited on Si substrate, the reaction between TiO2 and Si will happen to produce silicides. So a ZrO2 buffer layer with excellent thermal stability are used in this work. TiO2 films with various thicknesses have are deposited on the ZrO2 buffer layer and treated at 900℃ for lh successionally. Then the structures of TiO2 films with various thicknesses are studied with XRD and SEM. With the decrease of thickness, the intensity of diffraction peaks falls down and preferred orientation of （101） is apparent. TiO2 films with various thicknesses have compact structure. However, with the thickness cutting down to 30nm, there are a few shrinkage cavities appearing on grain boundary.