Mu Fengwen, Xu Yang, Shin Seongbin, Wang Yinghui, Xu Hengyu, Shang Haiping, Sun Yechao, Yue Lei, Tsuyuki Tatsurou, Suga Tadatomo, Wang Weibing, Chen Dapeng
Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, Shinjuku, Tokyo 169-0051, Japan.
Collaborative Research Center, Meisei University, Hino-shi, Tokyo 191-8506, Japan.
Micromachines (Basel). 2019 Sep 23;10(10):635. doi: 10.3390/mi10100635.
Wafer bonding of a silicon carbide (SiC) diaphragm to a patterned SiC substrate coated with aluminum nitride (AlN) film as an insulating layer is a promising choice to fabricate an all-SiC capacitive pressure sensor. To demonstrate the bonding feasibility, a crystalline AlN film with a root-mean-square (RMS) surface roughness less than ~0.70 nm was deposited on a SiC wafer by a pulsed direct current magnetron sputtering method. Room temperature wafer bonding of SiC-AlN by two surface activated bonding (SAB) methods (standard SAB and modified SAB with Si nano-layer sputtering deposition) was studied. Standard SAB failed in the bonding, while the modified SAB achieved the bonding with a bonding energy of ~1.6 J/m. Both the microstructure and composition of the interface were investigated to understand the bonding mechanisms. Additionally, the surface analyses were employed to confirm the interface investigation. Clear oxidation of the AlN film was found, which is assumed to be the failure reason of direct bonding by standard SAB.
将碳化硅（SiC）隔膜与涂有氮化铝（AlN）薄膜作为绝缘层的图案化SiC衬底进行晶圆键合，是制造全SiC电容式压力传感器的一个有前景的选择。为了证明键合的可行性，通过脉冲直流磁控溅射法在SiC晶圆上沉积了均方根（RMS）表面粗糙度小于约0.70 nm的晶体AlN薄膜。研究了通过两种表面活化键合（SAB）方法（标准SAB和具有Si纳米层溅射沉积的改进型SAB）在室温下进行SiC-AlN晶圆键合。标准SAB键合失败，而改进型SAB实现了键合，键合能量约为1.6 J/m²。研究了界面的微观结构和成分以了解键合机制。此外，采用表面分析来证实界面研究。发现AlN薄膜有明显氧化，这被认为是标准SAB直接键合失败的原因。
