Excimer-Laser-Induced Crystallization of Amorphous Silicon Films Deposited at 300°C Using Dehydrogenation by Argon Ion Implantation at 25 and 300°C

We report a processing method for forming polycrystalline silicon, poly-Si, films at 300°C. This method involves the deposition of 47-nm-thick hydrogenated amorphous silicon, a-Si:H, films at 300°C, followed by their dehydrogenation using Argon, Ar, ion implantation with a dose of 1x10
¹⁵
cm
⁻²
and an acceleration energy of 60 keV at 300°C, as well as at a room temperature of 25°C. Subsequently, pulsed excimer laser irradiation at 25°C is employed to crystallize the films. The 300°C-Ar implanted a-Si:H films were successfully crystallized by laser irradiation at 235
$\text{mJ}/\text{cm}^{2}$
, resulting in a crystalline volume ratio,
$X, \text{of}0.89$
while maintaining a smooth surface with a roughness factor,
$a_{\mathrm{R}}$
of 2.5. Similarly, the 25°C-Ar implanted a-Si:H films were also crystallized with an
$X_{\text{av}}$
,, of 0.91 and
$a_{\text{Rav}}$
, of 4.1. These results were comparable to
$X_{\text{av}}$
of 0.87 and
$a_{\text{Rav}}$
of 1.6 in the case of the 450°C-conventional thermal dehydrogenation. The Ar implantation effectively decreased the processing temperature required for forming poly-Si films via non-thermal equilibrium dehydrogenation.