Low temperature epitaxy and the importance of moisture control

Analysis of the Pre-epi Bake Conditions on the Defect Creation in Recessed SiGe S/D Junctions

“…In a first step, active area regions were defined by Shallow Trench Isolation (STI) followed by an n-well implantation. Before the selective epi deposition an HF-dip was performed (8,9). One of the parameters studied in this work is the waiting time (90 min) between the HF-dip and the loading of the wafer inside the reactor.…”

“…Subsequently, SEG of 100 or 140 nm in situ highly boron-doped Si, Si 0.85 Ge 0.15 or Si 0.75 Ge 0.25 epitaxial layers, was performed using an ASM Epsilon 3200 reactor. It should be noted that the moisture base-levels present in the reactor chamber at room-T are around ~ 5ppb with very small differences (a few tens of ppb) for variations of pressure and temperature (9). No implantation, nor anneal was done after the epitaxial deposition.…”

“…For the selective epitaxial growth process (21,22), an important factor which needs to be considered, is the optimization of the pre-epi clean, in order to remove the remaining traces of C and O on the starting Si surface, and therefore to enable a high quality epitaxial growth. Before the selective epitaxial deposition a wet-chemical HF-dip (8,9) was performed to remove the native oxide. Conversely, one issue which needs to be considered is that the oxide hard mask removal on the pMOS gate needs to be avoided.…”

“…It is well known, that the in situ H 2 bake conditions prior to epi deposition can affect the O and C contamination levels at the epi/substrate interface (8,9). An important factor is the thermal budget during the H 2 bake.…”

Deposition of O atomic layers on Si(100) substrates for epitaxial Si-O superlattices: investigation of the surface chemistry

“…Oxygen is usually considered as a contaminant for Si epitaxy [15]. Depending on the critical process parameters [16], the surface oxygen during the epitaxial growth will either desorb from the surface or oxidize the surface by forming SiO 2 . The presence of SiO 2 precipitates will lead to a growth of defective crystals thereon [15], or http://dx.doi.org/10.1016/j.apsusc.2014.…”