Layer Transfer and Simultaneous Crystallization Technique for Amorphous Si Films with Midair Structure Induced by Near-Infrared Semiconductor Diode Laser Irradiation and Its Application to Thin-Film Transistor Fabrication

Abstract

A novel layer transfer and simultaneous crystallization of amorphous silicon (a-Si) films induced by near-infrared semiconductor-diode-laser (SDL) irradiation has been investigated. The a-Si films supported by narrow quartz columns on a starting quartz substrate and a counter substrate [glass and poly(ethylene terephthalate)] were in face-to-face contact, and an SDL irradiated the a-Si films with midair structure. After SDL irradiation, the Si films were completely transferred and crystallized simultaneously on the counter substrates. In-situ monitoring revealed that the layer transfer took place either in the solid phase or the liquid phase followed by phase transformation in the cooling period. High performance polycrystalline Si thin-film transistors were successfully fabricated on the transferred Si films, which showed a high on/off ratio of more than 105 and a field-effect mobility as high as 268 cm2 V-1 s-1.

A technique for local area transfer and simultaneous crystallization of amorphous silicon layer with midair cavity by irradiation with near-infrared semiconductor diode laser

“…In our previous work, amorphous silicon (a-Si) films with a midair cavity were transferred to glass substrates and simultaneously crystallized by near-infrared semiconductor diode laser (SDL) irradiation. 26) It was shown that Si layers as large as 10 © 10 mm 2 area can be transferred using a Si film with a midair cavity (by controlling the position where quartz columns are formed). If the Si film can be "locally and repeatedly" transferred from a single starting substrate to a predetermined position on several different substrates by this transfer technique, the Si-use efficiency could be significantly improved.…”

“…Therefore, although the absorption of near-infrared light in the Si film is less than that of ultraviolet (UV) light, the Si film can be heated efficiently. 26) After the a-Si films with the midair cavity were irradiated by SDL at P of 60 W and scanning speed (v) of 2 mm/s, the patterned Si films were transferred to a counter glass substrate. Here, the Si film transfer from a single starting quartz substrate to two different glass substrates was carried out sequentially.…”

Low-temperature layer transfer of midair cavity silicon films to a poly(ethylene terephthalate) substrate by meniscus force

“…Quartz columns (with an area of 1 © 1 µm 2 ) were formed by controlling the duration of dipping in hydrofluoric acid. 11) The starting quartz substrate thus prepared and the counter-PET substrates were placed in close face-to-face contact, and 8 µL of pure water was sandwiched between them to form a water layer between the a-Si films and the PET substrates and to fill the midair cavity (see Fig. 1).…”

Fabricating metal-oxide-semiconductor field-effect transistors on a polyethylene terephthalate substrate by applying low-temperature layer transfer of a single-crystalline silicon layer by meniscus force

“…13,14 In a previous work, amorphous-silicon films with a midair cavity were simultaneously transferred to polyethylene terephthalate (PET) substrates and crystallized by using near-infrared semiconductor-diode-laser irradiation. 22 As for the important point of that work, it was shown that local layers of various shapes can be transferred by using Si film with a midair cavity (by controlling the position where quartz columns are formed). In the present work paper, a low-temperature technique for locally transferring siliconon-insulator (SOI) layers (supported by SiO 2 columns) from a starting SOI wafer by using meniscus force (without use of a laser) is proposed, and the performance of flexible MOSFETs fabricated by using a c-Si film transferred by this technique is verified experimentally.…”