Demonstration of 300 mm RF-SOI wafers fabricated by layer transfer technology.

State-of-the-art telecom applications have brought a real challenge to the radio-frequency silicon-on-insulator (RF-SOI) performance. This paper presents the key fabrication technologies for domestic 300 mm RF-SOI wafers fulfilling high-volume manufacture for the first time. To achieve stress relaxation, atmospheric pressure chemical vapor deposition (APCVD) coupled with annealing and chemical mechanical polishing (CMP) was applied to deposit the Poly-Si layer, resulting in a handle wafer with higher resistivity and lower warpage. Furthermore, integration of oxidation thinning and non-contact smoothing is proposed to eliminate the damaged layer caused by the layer transfer, through which surface roughness <3 Å and thickness uniformity <1% can be achieved. Based on power spectral density (PSD) analysis, we investigated the evolution law of different spatial frequency features of the Top-Si surface nano-topography obtained by oxidation thinning and non-contact smoothing. RF performance evaluated coplanar waveguides (CPW) reveals that substrate loss is below 4 dB cm and a second-order harmonic distortion (HD2) realized -95 dB m at 900 MHz, meeting the requirements for 5G devices. The batch-produced 300 mm RF-SOI has demonstrated excellent repeatability and reproducibility, signifying a breakthrough in domestic 300 mm RF-SOI.