Xu Tian, Zou Yali, Huang Xuan, Wu Junmin, Wu Shihao, Liu Yuhao, Xu Xuankai, Liu Fengyu
School of Microelectronics, Shanghai University, Shanghai 200444, China.
Changzhou Bawnovation Microelectronics Co., Ltd., Changzhou 213166, China.
Micromachines (Basel). 2023 Feb 28;14(3):583. doi: 10.3390/mi14030583.
When AlN thin films are deposited directly on the high-resistance silicon (HR-Si) substrate, a conductive layer will be formed on the HR-Si surface. This phenomenon is called the parasitic surface conduction (PSC) effect. The presence of the PSC effect will increase the power consumption of electronic components. Therefore, it is necessary to reduce the PSC effect. In prior technology, the polysilicon layer is usually used as the trap-rich layer to reduce the PSC effect. Experiments show that compared to AlN films deposited directly on HR-Si, the AlN substrates with polysilicon introduced on HR-Si have less radio frequency (RF) loss. To verify the effect of polysilicon on RF loss, polysilicon films of three different thicknesses and several different roughnesses were introduced. The results show that the thickness of the polysilicon will affect the RF loss, while the roughness has almost no effect on it. The polysilicon trap-rich layer can reduce the RF loss, which gradually becomes smaller as the polysilicon thickness increases.
当直接在高阻硅（HR-Si）衬底上沉积氮化铝（AlN）薄膜时，会在HR-Si表面形成一个导电层。这种现象被称为寄生表面传导（PSC）效应。PSC效应的存在会增加电子元件的功耗。因此，有必要降低PSC效应。在现有技术中，通常使用多晶硅层作为富陷阱层来降低PSC效应。实验表明，与直接沉积在HR-Si上的AlN薄膜相比，在HR-Si上引入多晶硅的AlN衬底具有更低的射频（RF）损耗。为了验证多晶硅对RF损耗的影响，引入了三种不同厚度和几种不同粗糙度的多晶硅薄膜。结果表明，多晶硅的厚度会影响RF损耗，而粗糙度对其几乎没有影响。多晶硅富陷阱层可以降低RF损耗，并且随着多晶硅厚度的增加，这种损耗会逐渐变小。
