Heteroepitaxial growth of oxide thin film on Si substrate by controlling the interface

控制界面在Si衬底上异质外延生长氧化物薄膜

基本信息

批准号：
07650362
负责人：
HORITA Susumu
金额：
$ 1.34万
依托单位：
Japan Advanced Institute of Science and Technology, Hokuriku
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650362/
关键词：
Yttria-Stabilized Zirconia Silicon Heteroepitaxial Growth Reactive Sputtering Sputtering Dielectric Materials

项目摘要

After the Y content dependence of YSZ film material properties was investigated, we confirmed usefulness of the YSZ buffer layr for the PZT film on Si.(1) 100-nm-thick cubic YSZ films with Y content ratios R_Y=2.3-19.7 at.% were heteroepitaxially grown on Si (100) at 800ﾟC and the crystal phase was kept at room temperature. Also, YSZ films with R_Y=1.2 at.% were kept to be cubic phase even at room temperature until their thickness were 20 nm. However, they were monoclinic at room temperature and were cubic at 800ﾟC when their thickness was more than 30 nm.(2) In the case of ZrO_2 without Y content, the 10-nm-thick (100) film grew heteroepitaxially on Si (100) substrate and the 100-nm-thick film had monoclinic (100) oriented grains which is about 9ﾟ off from the surface of the substrate.(3) We obtain electric characteristics of the YSZ films as follows : When the Y content was decreased and cubic phase was kept, the leakage current and the hysteresis width of the C (capacitance) -V (voltage) curve were increased. The hysteresis was due to ion drift. However, further decreasing Y content so that the crystal phase of the film was changed to monoclinic, the leakage current and the hysteresis width were decreased. This is probably because the crystalline quality of the film was degraded by decreasing the Y content in the state of the cubic phase.(4) When PZT film was deposited on the 10-nm-thick YSZ film with R_Y=9.4At.%, no reaction was found between the Si substrate and the PZT film and the ferroelectric property was observed. But, since the thickness of the YSZ film is not thin enough to reduce the operation voltage to 3V,we need to decrease its thickness and to improve the material quality of the film.

在研究了YSZ薄膜材料特性的Y含量依赖性后，我们证实了YSZ缓冲层对于Si上PZT薄膜的有用性。(1)100nm厚的立方YSZ薄膜，其Y含量比R_Y=2.3-19.7。％在800℃下在Si（100）上异质外延生长，并且晶相保持在室温下。 R_Y=1.2 at.% 即使在室温下，直至其厚度为20 nm，仍保持立方相，但在室温下为单斜晶相，当厚度超过30 nm 时，在800°C 下为立方相。(2)在ZrO_2不含Y的情况下,在Si(100)衬底上异质外延生长了10 nm厚的(100)薄膜, 100 nm 厚的薄膜具有单斜 (100) 取向的晶粒，距基底表面约 9°。 (3) 我们获得了 YSZ 薄膜的电特性如下：当 Y 含量减少且立方相减少时保持时，漏电流和C（电容）-V（电压）曲线的滞后宽度增加。滞后是由离子漂移引起的，然而，进一步降低Y含量，因此。薄膜的晶相变为单斜晶系，漏电流和滞后宽度减小，这可能是由于立方相状态下Y含量的降低导致薄膜的结晶质量下降。(4)当在R_Y=9.4At.%的10nm厚的YSZ薄膜上沉积PZT薄膜时，没有发现Si衬底和PZT薄膜之间发生反应，并且观察到铁电特性。但是，由于YSZ薄膜的厚度不足以将工作电压降低到3V，因此我们需要减小其厚度并提高薄膜的材料质量。