超薄LiTaO_3晶片的键合减薄技术

Ultrathin LiTaO_3 wafer prepared by wafer bonding and mechanical thinning processes

在制造红外热释电探测器阵列过程中,需要利用超薄钽酸锂(LiTaO3)晶片作为红外热释电探测器件的敏感层。通常LiTaO3晶片的厚度远厚于红外热释电探测器件要求的厚度,所以需要采用键合减薄技术对LiTaO3晶片进行加工处理。键合减薄技术主要包括:苯并环丁烯(BCB)键合、铣磨、抛光、加热剥离、刻蚀BCB。加工后得到面积为10 mm×10 mm、厚度为25μm的超薄单晶LiTaO3薄膜,晶片厚度、表面粗糙度和面形精度比较理想。测得了LT晶片减薄后的热释电系数为1.6×10-4Cm-2K-1。得到的单晶LiTaO3薄膜满足红外热释电探测器敏感层的要求。

Ultrathin LiTaO3 wafer is needed as a sensitive lay for fabricating high performance pyroelectric infrared sensor array. Since the thickness of LiTaO3 wafer was thicker than the required thickness, the LiTaO3wafer was processed by the novel wafer bonding and mechanical thinning processes, i. e. benzocyclobutene （BCB） bond stripping and BCB etching. The ultrathin single crystal lng,, LiT grinding, polishing, heating aO3 wafer with dimensions of 10 mm× 10 mm×25 μm was prepared with the thinning processes. The pyroelectric coefficient of the thinned LiTaO3wafer is 1.6 × 10^-4Cm^-2K^-1. The measured results of the thinned LiTaO3 wafer show that the thickness uniformity, surface roughness and surface profile accuracy can meet the requirement of the application.