Surface segregated Ga, In, and Al activation in high Ge content SiGe during UV melt laser induced non-equilibrium solidification

Abstract

The impact of solidification front velocity (SFV) on dopant segregation and activation surpassing the equilibrium solid solubility limit was investigated in high Ge content SiGe using UV nanosecond melt laser annealing (MLA). We first simulated the SFV evolution in the MLA-induced solidification of a SiGe binary system. It was then combined with the near-surface atomic and electrically active dopant concentrations measured in the Ga, In, and Al-implanted SiGe after MLA. Solute trapping phenomenon and self-compensation effect of the dopants were discussed to capture a part of their segregation and activation dynamics in the presented SiGeX ternary systems.

Recent Progresses and Perspectives of UV Laser Annealing Technologies for Advanced CMOS Devices

“…It should be noted that this k value is a function of the solidification front velocity (V) as shown in Figure 5 [48,49], and increasing V makes k become closer to the unity. For instance, antimony (Sb) in Si (i.e., n-type contact) shows such a surface segregation during ns UV-LA-induced LPER [42], and gallium (Ga) [39][40][41]43], aluminum (Al) [41], and indium (In) [41] in SiGe (i.e., p-type contact) also do (see Figure 6a,b) as experimental examples.…”

“…The first one is the liquid phase epitaxial regrowth (LPER), where the doped semiconductor is once melted and epitaxially regrown while activating the dopants. Typically, ns UV-LA enables this approach [34,[39][40][41][42][43]. In this article, when discussing LPER, we have a regime so-called "Secondary Melting (SM)" in mind rather than the one so-called "Explosive Melting (EM)".…”

Non-Equilibrium Growth of Surface Wrinkles Emerging in an SiO2/Si Stack during Si Melting Induced by UV Nanosecond Pulsed Laser Annealing

“…UV nanosecond pulsed laser annealing (UV-NLA) has been used in academic research for several decades, for example, to enable (i) metastable activation of an impurity in a semiconductor material by melting of materials and subsequent rapid solidification, [10][11][12][13][14][15][16][17][18][19][20][21] (ii) formation of an ultra-shallow junction, 22,23 and (iii) crystallization of amorphous silicon (Si) for a gate or a channel. 8,24 In parallel, some reports can be found on a trial of integrating laser anneal into industrial transistors, especially to reduce the contact resistivity.…”

Defect reduction and dopant activation of in situ phosphorus-doped silicon on a (111) silicon substrate using nanosecond laser annealing

“…Similar phenomenon was reported in the previous works about solute trapping phenomenon in ultra-rapid solidifications. [21][22][23] During the solidification in laser annealing, the velocity of the liquidsolid interface (solidification front velocity) is ∼4 m s − 1 21) that is faster than dopant diffusion velocity in the interface (∼1 m s −1 ), 23,24) and thus the dopant in the solidification interface could not diffuse out the molten silicon 21,22) and the uniform distribution of phosphorus is maintained. The phosphorous atoms in the initial 40 nm thick ISPD silicon layer was the redistributed in the 60 nm thick silicon after NLA, the phosphorus concentration therein decreased from 4 × 10 21 to 2.7 × 10 21 cm −3 , which is well matched with the calculation results.…”