Improving the quality of the evaporated Ge nanodot arrays by laser annealing
Journal
IEEE Conference on Nanotechnology
Pages
1699-1702
Date Issued
2011
Author(s)
CHIEH-HSIUNG KUAN
Liao, T.-W.
Wu, Y.-K.
Chiu, C.-W.
Chen, H.-M.
CHIEH-HSIUNG KUAN
Abstract
To improve the quality of deposited amorphous germanium (a-Ge) on the Si substrate, a re-crystallization method of a-Ge by laser annealing is demonstrated. Laser annealing has two important advantages: high energy density E (700, mJ/cm 2 ) is melting the a-Ge and a lot of laser spot quantity (20 spots) is alteration the a-Ge quality. These two factors were carefully designed to fabricate the high quality crystalline Ge(c-Ge). High laser energy density E and a lot of laser spot quantity would transform the a-Ge nanorod into c-Ge nanodot due to Ge's high cohesion. In addition, the size and distribution of Ge-nanodot arrays can be defined with the electron beam (E-Beam) lithography. The quality of re-crystallized Ge-nanodot arrays as characterized with Micro-Raman. To characterize the crystallinity, the Raman spectrum is fitted with the Lorentz distribution. The result shows that the narrow FWHM is 3.5278 cm -1 and peak position at 303.889 cm -1 , which is close to that of single crystal Ge. It implies that the quality of there crystallized Ge-nanodot arrays are almost the same as that of single crystal Ge and the strain is fully relaxed. In summary, the high quality of crystalline germanium (c-Ge) nanodot arrays on Si substrate can be achieved by laser annealing.
SDGs
Type
conference paper