Laser crystallization of silicon for high-performance thin-film transistors

Abstract

We crystallize amorphous silicon films by a frequency doubled Nd:YVO 4 laser with a pulse energy of 18.5 µJ and a repetition frequency of 20 kHz. A sequential lateral solidification process yields polycrystalline silicon with grains longer than the channel of thin-film transistors. The resulting electron field effect mobility of 410 cm 2 V −1 s −1 shows the superiority of our process compared with excimer laser crystallization. A calculation results in a possible throughput of 35 cm 2 s −1 for our laser crystallization process if one used a laser with a pulse energy of 1.25 mJ and a repetition frequency of 100 kHz.

BV‐2 microglial cells sense micro‐nanotextured silicon surface topology

“…The use of pulsed laser beams is one of the leading techniques in the fabrication of polycrystalline silicon (poly-Si) layers used as an active material in thin-film transistors, solar cells, and field emission devices. [17][18][19] Micro-nanostructures generated by the laser beam interactions and chemical or plasma etching of silicon wafers are often expensive due to the technical complications of silicon wafer processing. In this work, we describe processes that easily produce optically modulating structures from excimer laser processing of thin hydrogenated amorphous silicon films deposited by plasma-enhanced chemical vapor deposition (PECVD) on glass substrates.…”

42.4: Characterization of Electrochemically‐Active Defects in Si‐Film Laser‐Crystallized with Directional SLS by Measuring the Stress Release during Secco Etching

“…The electrochemically-active in-grain defects in CLC films have been recently shown to be very little compared to that of ELC [9]. The directional SLS crystallized by a pulse solid-state laser [10] or a pulse excimer laser [11,12] also produces an extended lateral growth regions, having the similar almost parallel grain-boundary patterns as those of CLC.…”

Study of a-Si crystallization dependence on power and irradiation time using a CW green laser

“…However, the traditionally used excimer laser crystallization (ELC) has some disadvantages, mainly the narrow process window of laser energy density and the maximum crystallization depth achievable with this method. In recent works other lasers have been studied, like pulsed Nd:YAG lasers (1064 nm, 532 nm and 355 nm) [9][10], CW green laser [11][12][13][14][15], and CW diode lasers (808 nm) [16][17]. Laser silicon crystallization using these wavelengths and pulse times allows a large variety of grains structure depending on the laser power and the scanning speed, leading to a very wide processing window [18], in opposite to the conventional excimer laser crystallization (ELC) process where the super lateral growth (SLG) regime is very difficult to determine [5].…”