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90 - nm -thick a-Ge films were melted and solidified by excimer laser annealing method. The superlateral growth (SLG) distance increased from 0.5to4.1μm with increasing absorption coefficient of the light-absorptive underlayer. Real-time reflectivity measurement revealed that the increase in the SLG distance resulted from an increase in the Ge film solidification term from 60to650ns. The SLG velocity calculated from the proportionality constant of the SLG distance and the solidification term was 6–7m∕s. It was shown that SLG grains exhibit a single-crystalline structure.

This paper presents a 28-GHz CMOS four-element phased-array transceiver chip for the fifth-generation mobile network (5G) new radio (NR). The proposed transceiver is based on the local-oscillator (LO) phase-shifting architecture, and it achieves quasi-continuous phase tuning with less than 0.2-dB radio frequency (RF) gain variation and 0.3 • phase error. Accurate beam control with suppressed sidelobe level during beam steering could be supported by this work. At 28 GHz, a single-element transmitter-mode output P 1 dB of 15.7 dBm and a receiver-mode noise figure (NF) of 4.1 dB are achieved. The eight-element transceiver modules developed in this work are capable of scanning the beam from −50 • to +50 • with less than −9-dB sidelobe level. A saturated equivalent isotropic radiated power (EIRP) of 39.8 dBm is achieved at 0 • scan. In a 5-m overthe-air measurement, the proposed module demonstrates the first 512 quadrature amplitude modulation (QAM) constellation in the 28-GHz band. A data stream of 6.4 Gb/s in 256-QAM could be supported within a beam angle of ±50 • . The achieved maximum data rate is 15 Gb/s in 64-QAM. The proposed transceiver chip consumes 1.2 W/chip in transmitter mode and 0.59 W/chip in receiver mode.