20‐μm‐wide, 1‐mm‐long, single‐crystal Si films on SiO2 have been produced using a cw Ar laser beam split by a birefringent quartz plate. The single‐scan recrystallized region width has been widened by multiple beam splitting. The resultant single‐crystal region obtained by multiple scan from the seed is a 90‐μm‐wide and 100‐μm‐long area with rare grain boundaries. This split beam method uses the stable and highly efficient TEM00 mode and needs no prepatterned antireflection layers.

Recrystallization of silicon film on insulating layers using a laser beam split by a birefringent plate

Comprehensive and systematic studies on the growth characteristics of SOI (silicon‐on‐insulator) films recrystallized by an obliquely scanned pseudoline electron beam are presented. The obliquely scanned pseudoline beam was produced by scanning a spot electron beam along a line faster than the thermal response time of the substrate and it was moved as a whole to a different direction from the normal direction of the line. In the experiment of laterally seeded epitaxial growth of SOI films, the pseudoline beam was always scanned along the seed stripes, while the direction of the seed stripes to the Si substrate and an oblique angle between the scanning direction and the normal direction of the line were changed. It was found that the sub‐boundary‐free area in the SOI film was enhanced either by increasing the oblique angle or by rotating the seed direction from a 〈110〉 to 〈100〉 axis of the substrate. It was also found that the directions of sub‐boundaries hardly depended on the oblique angle but they were ...

Characterization of silicon‐on‐insulator films recrystallized by an obliquely scanned pseudoline electron beam

Seeding lateral epitaxy for silicon films on an insulator, using pseudoline shaped electron beam annealing, has been investigated. Higher oscillation frequency, higher beam scanning velocity, and suitable oscillation amplitude were effective to achieve large uniform silicon on insulator (SOI) films with the aid of simulating temperature distribution in silicon substrate. Furthermore, improved seed with tapered edge and capping layer of tungsten/insulator were employed to obtain 300 μm×1.3 mm single‐crystal SOI films on a 1.3‐μm SiO2 layer. Stacked SOI devices were successfully fabricated with low‐temperature planarization process. 218 ps/stage propagation delay and 17 pJ power‐delay product were obtained.

Seeding lateral epitaxy of silicon on insulator with improved seed and cap structure by pseudoline shaped electron beam annealing

Formation of silicon-on-insulator layers by electron beam recrystallization

E-beam recrystallization has been applied to the fabrication of a three-layer processor. The seed structure and the E-beam conditions were successfully optimized so that a large-area SOI as wide as 1 mm was recrystallized without void generation with no damage to underlying devices. The actual SOI area in the device, 850*1100 mu m, was recrystallized with one E-beam scan by aligning its position. The three-layer image processor was capable of visual image sensing with a feature outline extraction in a parallel processing manner. Normal operations of the fundamental functions have been confirmed, demonstrating the feasibility of E-beam recrystallization for three-dimensional IC application. >

M. Nakano

Papers

Recrystallization of Silicon-on-Insulator Structures by an Electron-Beam with Fast Sinusoidal X- and Slow Linear Y-Scans