Control of Boron and Phosphorus Transient Enhanced Diffusion (TED) is the key to the development of high performance n and p type Ultra Shallow Junctions (USJ). Carbon, Fluorine, and Germanium co-implants can be used to reduce or modify the Boron or Phosphorus Interstitialcy Clusters (BIC or PIC) that drive TED. Substitutional Carbon (Cs) or Fluorine-Vacancy (F-V) clusters do this by consuming the interstitials that drive TED by Carbon Kick-out or F-V annihilation. Germanium does this by inhibiting Interstitialcy formation through local lattice strain. It has been found that certain combinations of these techniques can combine to maximize TED reduction and several of the mechanisms have been characterized. Low energy 5keV Germanium and Carbon have yielded a Boron USJ with a junction depth (xj) of 16.8 nm and a sheet resistance (Rs) of 602 Ω/□, while 8keV Fluorine and Carbon have formed a Phosphorus USJ with xj = 29.5 nm and Rs ≈ 150 Ω/□. In addition record levels of Boron TED control have been found using Carbon and 12keV Phosphorus co-implants (xj = 13.3 nm). Record levels of Phosphorus TED control have been found using Carbon and 4keV Boron co-implants (xj = 22.2 nm). In these cases the counter-dopant below the USJ is probably forming PIC or BIC consuming interstitials more efficiently than non-electrical dopants dramatically limiting TED. For Phosphorus USJ there is a strong TED dependence on Boron co-implant energy. Uphill diffusion has been observed if the Phosphorus implant energy is below 3 keV, or without amorphization, and increases as Boron co-implant energy decreases. This work has also found the first experimental evidence of F-V clustering acting to limit TED in USJ by toggling the order of Halo implantation which generates a vacancy distribution. This causes a change in Boron diffusion that is well explained by the lack or presence of the F-V clusters. In addition, Phosphorus TED shows a slight decrease as Fluorine co-implant energy decreases and seems to optimally place the F-V clusters at 8keV.
|School:||Arizona State University|
|School Location:||United States -- Arizona|
|Source:||DAI-B 69/04, Dissertation Abstracts International|
|Keywords:||Boron, Co-implantation, Diffusion, Phosphorus|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be