Pulsed excimer laser deposition of Si1−xGex thin films

Abstract

FIG. 1. Random RBS spectra of the SiGe target ͑1͒ before and ͑2͒ after a multipulse laser ablation with an energy fluence of 2 J cm Ϫ2 .

Stoichiometry issues in pulsed-laser deposition of alloys grown from multicomponent targets

“…After subsequent shots on the target, the average film composition decreases to what appears to be a steady state composition of 32% Ge. This steady state result is consistent with the previous work by Antoni et al [4] who found a Ge composition between 35 and 40% for a 20% Ge target. The results for the sintered target show a similar trend, leading to a steady state composition which is also greater than the target composition.…”

“…Target effects include preferential ablation from the target [9], thermal evaporation at low energy due to different vapor pressures [6], or segregation occurring at the target surface [4]. The first two effects are unlikely in this experiment since we are dealing with energies well beyond the ablation threshold for Si or Ge.…”

“…However, it is well known that such favorable results do not occur under all experimental conditions. Systems ranging from simple two-component metallic systems [2,3] and semiconductor systems [4], to more complicated superconducting oxides [5] and ferroelectrics [6] have shown non-stoichiometric transfer of the target composition. The majority of the literature focuses on techniques to overcome this obstacle.…”

Stoichiometry issues in pulsed-laser deposition of alloys grown from multicomponent targets

“…This enrichment was previously observed in the SiGe system [4], and we observe it in our RBS analysis of the target after laser irradiation. However, target segregation itself is not sufficient to describe noncongruent transfer in the steady state, regardless of the system being studied.…”

The Properties of Ge Quantum Rings Deposited by Pulsed Laser Deposition

“…For example, Antoni et al reported that Ge quantum dots and quantum ring were prepared from the droplets. 4 However, the film was a mixture of the dots and rings, and there existed a considerable variation in their sizes and shapes. In this paper, we try to grow the pure quantum ring structures of Ge using the PLD technique based on the elastic deformation of the droplets.…”