Polycrystalline Silicon Thin Films Produced by Interference Laser Crystallization of Amorphous Silicon

Abstract

Pulsed interference laser crystallization of amorphous silicon has been applied to produce polycrystalline silicon thin films with grain sizes exceeding 5 µm. It has been achieved by shifting the samples through the interference pattern, with steps of typical 100 nm width. Grain sizes have been investigated by atomic force microscopy (AFM). The grains show quadratic shapes with a typical length of the applied interference period (5 µm) and width around 1.5-2.5 µm.

Spatially localized current-induced crystallization of amorphous silicon films

“…Therefore, crystallization of amorphous silicon films is traditionally studied as an alternative method for producing large area electronics such as displays and solar cells. Crystallization is typically induced by laser annealing [3] or high temperature furnace annealing [4]. Presence of silicide forming metals such as nickel [5] or application of electric field [6,7] was found to reduce the crystallization temperature.…”

Location control of crystal grains in excimer laser crystallization of silicon thin films

“…2 Various methods of controlling the GB location have been proposed in the rapid melting and recrystallization by laser annealing of a-Si thin films. They can be classified under the dimensionality of the control into the one dimensional [3][4][5][6][7][8][9][10][11][12][13][14] or the two dimensional. [15][16][17][18][19][20][21][22][23][24][25][26][27] In these previous attempts, the location of the grain formation is controlled either by ͑1͒ some means to manipulate the spatial distribution of temperature in the molten thin films, such as the spatial modulation of the laser intensity, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]20,21,26 the sequential lateral solidification by scanning line-shaped laser beams stepwise 4,8,…”

A reliable approach to a rapid calculation of the grain size of polycrystalline thin films after excimer laser crystallization

“…Before the FE-SEM observation, the crystallized silicon films were Secco-etched in order to highlight the grain boundaries (GBs) and intra-grain defects. 27 The acceleration electron beam energy for FE-SEM was 15 kV (a resolution of 1.5 nm). Six approaches (count, auto-split, watershed split, limited watershed split, boundary definition and selected-boundary definition) were employed for calculating the grain size of the poly-Si thin films.…”