John J. Hautala

SOI thickness uniformity improvement using corrective etching for silicon nano-photonic device

We present our recent results on Si thickness uniformity improvement in a SOI wafer. We improved the thickness uniformity by 50%. The effect of the correction process on the propagation loss and device uniformity is also presented.

Productivity Enhancements for Shallow Junctions and DRAM Applications using Infusion Doping

The inherent challenges for traditional ion implanters to deliver sufficiently high beam currents at sufficiently low energies required for shallow doping applications such as USJ and polysilicon doping for DRAM and has motivated the development of alternative methods for shallow doping. These include large molecule implantation, plasma doping and infusion doping with ionized gas clusters. Recent advancements in infusion doping have led to a very high flux (>100mA) of boron at low equivalent monomer implant energies (<1keV). In addition to producing uniquely high equivalent beam currents, the infusion process is physically distinct from implantation (beamline, molecular, or plasma) in the following important ways : (1) the doping depth is independent of species mass; (2) the doping depth is proportional to the one third power of the acceleration energy; (3) infusion doping is fully self‐amorphizing with no evidence of channeling or end of range (EOR) damage; (4) there is no evidence of any self‐sputtering...

Comparison of RF bias, gas cluster ion beam, and ion beam in-situ beam treatment for enhancement of GMR in spin-valve stacks

In this paper, we present data comparing three different in-situ beam treatment (smoothing) techniques for enhancement of GMR properties. The three techniques were radio-frequency bias (RFB), gas cluster ion beam (GCIB), and ion beam (IB). All three were optimized for maximum enhancement of properties and resulted in an increase of GMR of about 0.5 to 1% (> 13.5% to > 14.5%) and a reduction in interlayer coupling of about 15 to 30 Oe (5 Oe to -25 Oe) when treating the CoFe/Cu interface of a synthetic pinned bottom spin valve. Smoothing the Ru/CoFe interface resulted in enhancement of GMR, but no change in the interlayer coupling. The optimum conditions for all three techniques corresponded to ion bombardment energies in the range of 10-60 eV. For RFB, the substrate bias voltage was optimized at 60 V, for IB, the extraction energy was 30 eV, and for GCIB, the equivalent energy/atom was in the same range. Our results indicate that all three smoothing methods are effective in improving the GMR properties with no fundamental advantage of any particular technique.

Infusion doping for USJ formation

We report for the first time results on infusion doping of boron for ultra shallow junctions (USJ). Using B/sub 2/H/sub 6/ or BF/sub 3/ source gas, the resulting USJ boron dopant profile measured by SIMS shows no evidence of channeling with extreme abruptness of <2.5nm/decade for a 12 nm shallow junction. Infusion doping shows a power log to the 1/3 relationship between energy to junction depth in contrast to the traditional linear fit observed with ion implantation due to nuclear stopping power effects. Boron surface doping levels of 1-2E22/cm/sup 3/ for 2E16/cm/sup 2/ doses were achieved. Dopant activation using low temperature furnace annealing from 450/spl deg/C to 950/spl deg/C were compared using standard 4PP and non-penetrating elastic material 4PP for sheet resistance measurements,on these USJ structures. Also, electrically active dopant profiling was conducted using spreading resistance profile (SRP) for USJ junction depth (Xj) comparison to SIMS. Use of amorphizing implantation resulted in lower Rs values after low temperature SPE annealing.

Infusion processing for advanced transistor manufacturing

Production capable infusion processing equipment for ultra shallow doping and surface engineering is now available. Shrinking device dimensions require extremely shallow doping for many applications. New techniques are necessary in order to manufacture source drain extensions (SDE) and for DRAM poly doping. Channel engineering is required for advanced gates. High throughput, tight process control and low contamination are required from the process equipment. Epion Corporation has developed the nFusiontrade 300mm doping system that offers solutions for these applications. The production worthiness is characterized with high doping rates, long term repeatability, depth control and low contamination

Nano-oxide layer formed on ruthenium of synthetic pinned-structure spin valve by ion beam and cluster ion beam oxidation

In this paper, we report the performance of bottom synthetic spin-valve films with a newly developed ruthenium (Ru)-based nano-oxide layer (NOL). Two energetic oxidation techniques using an ion beam and a gas cluster ion beam were applied for the formation of the Ru NOL in the synthetic pinned layer. The giant magnetoresistance (GMR) was greatly enhanced from 13.8% to 15.7% with no sign of degradation in the pinning strength. In addition, these Ru NOL-bearing spin-valve films have demonstrated an excellent thermal stability, withstanding repeated thermal annealing cycles at elevated temperatures. This performance is clearly superior to that from the spin-valve films with a conventional CoFe-based NOL. The Ru NOL has shown a great potential for high-amplitude read sensor applications.