Aluminum-induced crystallization of amorphous silicon

Interdiffusion in microstructurally different Si/Al multilayered structures

“…1.27 eV for Si/Al multilayer by DSC (Differential Scanning Calorimetry), 13 1.17 eV for Si/Al bilayer by focused ion beam microscopy (FIB), 14 and 1.80 eV for Si/Al bilayer by optical micrographs. 15 It appears that the crystallization of Si is initiated by crystallization of Si that had diffused along grain boundaries in Al (for detailed discussion, see Ref. 9) and that this grain boundary diffusion of Si is crystallization rate controlling.…”

Thin polycrystalline SiGe films by aluminium‐induced layer exchange

“…The silicon layer moves from the top to the bottom of the stack and is transformed into polycrystalline silicon on the way, whereas the aluminium layer exchanges its position from the bottom to the top of the stack, where it can be removed easily by selective wet chemical etching, leaving behind the polycrystalline silicon film. Further details of this process have been investigated by various groups [14][15][16][17][18]. Nast et al have observed that the ratio of the initial Si and Al layer thickness is important for the formation of a closed poly-Si layer after the ALILE process.…”

“…Aberle et al also were able to demonstrate the feasibility of epitaxial thickening of thin Si seed layers produced by the ALILE process via suitable low temperature deposition techniques [17]. Gall et al have investigated the nucleation and growth kinetics of the ALILE process [18]. In particular, these authors report an activation energy of about 1.8 eV for the nucleation of Si-crystallites during ALILE.…”

“…Following a method developed e.g. by Gall et al [18], the ALILE process can be observed in real time with a video microscope focussed onto the interface between the transparent substrate and the AlSiGe film. Initially, the interface is highly reflecting due to the Al layer.…”

Structural properties of a-Si films and their effect on aluminum induced crystallization

“…Both of these techniques have important advantages from an application standpoint: e-beam evaporation enables high deposition rates and a precise doping profile, whereas PECVD is more compatible with large area applications. In addition, while many parameters affecting the AIC process such as annealing temperature, 6 Al grain structure 7,8 and thickness and structure of the AlO x layer at the Si/Al interface 9,10 have been previously studied; the influence of the a-Si layer on AIC layer has largely been unexplored (barring a study focusing on the hydrogen content of sputtered a-Si films 11 ). The AIC experiments were carried out using a a-Si/Al/SiN x /glass stack configuration, wherein the SiN x layer serves as a buffer to prevent any contamination from the glass substrate.…”