Hot Implantations of P into Ge: Impact on the Diffusion Profile

Abstract

The impact of the Ge substrate temperature on the P implantation profiles has been investigated. It is shown that hot implantations at 350 or 400 • C result in deeper concentration profiles due to the implantation-enhanced channeling at high temperature. Meanwhile, the amorphous layer thickness decreased significantly by dynamic annealing. According to HR-XRD scans end-of-range (EOR) damage is formed during the hot implantation. Subsequent Rapid Thermal Annealing at 500 • C for 1 min leads to a standard box-like profile for the wafer implanted at room temperature and to accumulate P at the EOR damage region for the 350 and 400 • C hot

Defect engineering for shallow n‐type junctions in germanium: Facts and fiction

“…a). The shallowest junction is obtained for the 8 keV C implantation (dose 1 × 10 15 at cm −2 ) . In all co‐doped cases, a shallower P profile has been achieved compared with the P only condition, which shows the traditional box‐like profile after RTA .…”

“…The a/c interface is indicated by the vertical dashed lines. It is approximately 34 nm, except for the 15 keV C case, where it increases to 41 nm .…”

“…The two vacancy profiles correspond with the PAI damage and the vacancy profile created by the C implantation (as the P is implanted in an a‐Ge layer, there will be negligible contribution to the V profiles). A detailed analysis of these simulation results has shown that the optimum C condition corresponds with the presence of a sufficient carbon concentration below the a/c interface, while at the same time, the associated damage should be small enough, i.e., the concentration of carbon ion‐implantation‐induced vacancies below the interface in the c‐Ge should not overwhelm the Ge PAI damage . In this way, one assures that there are sufficient C atoms below the a/c interface to trap PV pairs.…”

“…In order to gain more insight in the effect of C co‐doping, a systematic study with respect to the implantation parameters (C dose and energy) has been undertaken as described in more detail elsewhere . Besides the chemical profiles by SIMS, electrical characterization has been carried out to derive the active level.…”

Improved retention of phosphorus donors in germanium using a non-amorphizing fluorine co-implantation technique

“…single dose delivery at room temperature). However, we describe two novel approaches to achieve high concentrations of fluorine without amorphizing the germanium: 1) via consecutive, low dose fluorine implants, intertwined with RTA, which partially suppresses cumulative damage 'build-up' (we refer to this as "intertwined" implantation), or 2) by implanting into a 'hot' (200 o C) wafer, which has the effect of increasing the dynamic annealing of the Frenkel pairs resulting in a lower rate of vacancy defect generation [33] (we refer to this as "hot wafer" implantation) [19].…”