CVD法制备的高结晶质量二维β-Ga_(2)O_(3)薄膜性质研究

为了能够得到高质量的薄膜,降低实验成本,通过化学气相沉积(CVD)方法以GaTe粉作为Ga源在云母衬底上合成了β-Ga_(2)O_(3)薄膜。通过改变生长温度、载气和生长时间得到高结晶质量的β-Ga_(2)O_(3)薄膜,并通过X射线衍射(XRD)和拉曼光谱进行证实。XRD结果显示,薄膜的最佳生长温度为750℃。对比不同载气下合成的β-Ga_(2)O_(3)薄膜可知,Ar气是生长薄膜材料的最佳环境。为了实现高结晶质量的β-Ga_(2)O_(3)薄膜,在Ar气环境下改变薄膜的生长时间,XRD结果发现,生长时间20 min的薄膜具有高结晶质量。最后,将其转移到300 nm厚氧化层的Si/SiO_(2)衬底上,并通过原子力显微镜测试,证实了16 nm厚的二维Ga_(2)O_(3)薄膜。

Development of Ferroelectric RAM （FRAM） for Mass Production

we have developed ferroelectric capacitor fabrication technique to realize low-voltage and high-density ferroelectric random access memory （FRAM）. High temperature deposited IrOxtop electrode reveals high crystalline quality which drastically reduces the degradation of ferroelectric film by preventing hydrogen diffusion into ferroelectric film. This improvement enables us to commercialize highly-reliable 1T 1C FRAM with memory density of 4 Mb or larger.