Crystallization of electron beam evaporated a-Si films on textured glass substrates by flash lamp annealing

Abstract

We investigate the crystallization of amorphous silicon (a-Si) films, by flash lamp annealing (FLA), formed by electron beam (EB) evaporation on textured glass substrates. We confirmed that EB-evaporated a-Si films formed on textured glass can be crystallized by FLA. Optical reflectance on EB-evaporated a-Si can be reduced by using the textured glass, leading to a reduction in the fluence of a FL pulse required for the crystallization. The fluence of a FL pulse for the crystallization of EB-evaporated a-Si films tends to increase with temperature during EB evaporation of a-Si films. The pre-existing crystal grains in precursor Si films may affect the mechanism of their crystallization. The usage of textured glass substrates leads the formation of polycrystalline Si (poly-Si) films with fine grains. This may result from the prevention of lateral thermal growth and the suppression of explosive crystallization (EC). Unlike in the case of the crystallization of EB-evaporated a-Si films on flat glass substrates, poly-Si films formed on textured glass substrates are not cracked. This may be due to the suppression of the emergence of EC.

Crystallization of catalytic CVD hydrogenated n-a-Si films on textured glass substrates by flash lamp annealing

“…27) In addition, due to the passivation effect of the SiN x film and the absence of the Cr adhesion layer, the thin-film poly-Si solar cells with higher conversion efficiency than those on Cr films will be obtained. 21) Figure 3 shows the surfaces of i-and n-poly-Si films on SiN x -coated textured glass after FLA at sub-pulse emission frequencies of 1, 2, 4, 6 and 10 kHz, respectively. All the samples have macroscopic stripe patterns and the width of the stripe changes with sub-pulse emission frequency.…”

“…We previously found that EBevaporated a-Si films on glass substrates textured by RIE can be crystallized through EC. 21,22) Similar crystallization and anchor effect can also be seen when a Si nitride (SiN x ) film is inserted between a-Si and textured glass, which will act as a passivation and anti-reflection (AR) film for the back-contact cell. 22) In this study, we attempted to crystallize Cat-CVD a-Si:H films by FLA on SiN x -coated textured glass substrates.…”

“…14) We have attempted to use precursor a-Si films formed by various types of deposition methods, such as catalytic chemical vapor deposition (Cat-CVD), sputtering, and electron-beam (EB) evaporation. [15][16][17][18][19][20][21][22][23][24] The crystallization of EBevaporated a-Si films on flat glass substrates is driven by liquid-phase explosive crystallization (EC), which leads to the formation of crystal grains with a size of several tens of μm. 17) A different type of EC occurs for the crystallization of Cat-CVD a-Si:H films, through which two types of regions with different microstructures appear alternately in the direction of crystallization with a period of ∼1 μm.…”

Электронно-Пучковая Кристаллизация Тонких Пленок Аморфного Субоксида Кремния

“…Наиболее распространенным способом получения тонких пленок poly-Si на низкотемпературных подложках является кристаллизация пленок аморфного кремния (a-Si). Среди методов кристаллизации, которые используют прямое воздействие на исходную пленку кремния, можно выделить лазерный отжиг (laser annealing) [3], импульсный фотонный отжиг (flash lamp annealing) [4], отжиг термоплазменной струей (thermal plasma jet) [5], электронно-пучковую кристаллизацию (electron beam crystallization) [6,7].…”