The crystallization of amorphous germanium films

Ultra-doped n-type germanium thin films for sensing in the mid-infrared

“…According to the reported data from calorimetric studies, e.g. in refs 33,37, in our case the incubation time of crystalline seeds and the recrystallization speed are expected to be in the range of 1 μs and 1 × 10 −4  m/s, respectively. On the other hand, L. Nikolova et al .…”

“…This has a strong influence on the distribution of dopants in Ge, especially on the fast diffuser phosphorus and on the recrystallization process during the sub-second flash annealing. In order to explain the recrystallization mechanism of an implanted Ge layer during f-FLA, the different values of the activation energy and the pre-factor for seed nucleation and solid phase epitaxy as well as the temperature gradient within the amorphous layer and the speed of heat dissipation have to be taken into account303132333435363738. Moreover, the incubation time of crystalline seeds at the surface for the random nucleation has to be considered.…”

Investigation of crystallized germanium thin films and germanium/silicon heterojunction devices for optoelectronic applications

“…It should be noted that while according to Ref. [2], annealing for 30 min at T4490 1C should be sufficient to fully crystallize amorphous Ge films, Blum and Fedlman indicate that substrate, deposition method and sample preparation may have significant influence in the crystallization process [2]. The diffraction peaks at 2θ¼ 27.381, 45.441, and 53.841 were assigned to the (111), (220), and (311) planes, respectively.…”

“…Germanium is a relatively well-understood semiconductor material owing to several decades of research [1][2][3][4][5], and has recently experienced renewed interest as a mobilityenhancement channel material for advanced MOSFET devices [6][7][8][9], and as a narrow bandgap material for near-infrared wavelength photodetectors [10,11]. Additionally, germanium has found widespread application as the bottom cell in multijunction solar cells because of its low energy bandgap (0.67 eV) and favorable optical absorption properties [12,13].…”

Enhancement of carrier mobility in thin Ge layer by Sn co-doping

“…The fabricated GeSn alloy films show the direct optical band gap for Sn concentration above 8% [13]. To this day, the GeSn films are mainly made by deposition techniques like molecular beam epitaxy and chemical vapour deposition [13,14]. But GeSn alloy can be also fabricated by Sn implantation into a Ge film and post-implantation nonequilibrium thermal processing like nanosecond pulsed laser annealing (PLA) [11].…”