Low Energy Implantation and Transient Enhanced Diffusion: Physical Mechanisms and Technology Implications

1997 ◽  
Vol 469 ◽  
Author(s):  
N. E. B. Cowern ◽  
E. J. H. Collart ◽  
J. Politiek ◽  
P. H. L. Bancken ◽  
J. G. M. Van Berkum ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Crystalline Silicon ◽  
Cmos Technology ◽  
Low Energy ◽  
Defect Engineering ◽  
Enhanced Diffusion ◽  
Physical Mechanisms ◽  
Transient Enhanced Diffusion ◽  
Junction Formation ◽  
Silicon Cmos

ABSTRACTLow energy implantation is currently the most promising option for shallow junction formation in the next generations of silicon CMOS technology. Of the dopants that have to be implanted, boron is the most problematic because of its low stopping power (large penetration depth) and its tendency to undergo transient enhanced diffusion and clustering during thermal activation. This paper reports recent advances in our understanding of low energy B implants in crystalline silicon. In general, satisfactory source-drain junction depths and sheet resistances are achievable down to 0.18 micron CMOS technology without the need for implantation of molecular species such as BF2. With the help of defect engineering it may be possible to reach smaller device dimensions. However, there are some major surprises in the physical mechanisms involved in implant profile formation, transient enhanced diffusion and electrical activation of these implants, which may influence further progress with this technology. Some initial attempts to understand and model these effects will be described.

Transient Enhanced Diffusion for Ultra Low Energy Boron, Phosphorus, and Arsenic Implantation in Silicon

1998 ◽  
Vol 532 ◽  
Author(s):  
Ning Yu ◽  
Amitabh Jain ◽  
Doug Mercer
Keyword(s):  
Ion Implantation ◽  
Process Development ◽  
Cmos Technology ◽  
Low Energy ◽  
Defect Engineering ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Ultra Shallow Junctions ◽  
Technology Nodes ◽  
The Impact

ABSTRACTThe SIA roadmap predicts that junction depths of 500 angstroms are required for CMOS technology nodes of 0.18 μm or beyond by the year 2001. There are several ultra-shallow junction doping techniques currently under investigation. These include beamline ion implantation, plasma immersion ion implantation, and gas immersion laser doping. This study was based on beamline ion implantation of B, P, and As into single-crystal Si wafers at 0.25-2 keV to doses of (2- 10)×1014 at./cm2 with minimized beam energy contamination. Rapid thermal annealing was applied to the implanted wafers at 1000-1050 °C for 10-15 sec at ramp rates of 35- 50 °C/s in a N2 ambient. Transient enhanced diffusion was observed for all three implant species. For example, the depth of 0.25 keV B measured by SIMS increases from 250 to 520 A at a concentration level of l×1017 at./cm3 upon RTA. To minimize the TED, several schemes of defect engineering were applied prior to low energy implantation, including pre-amorphization and implantation of other species. A comparison of TED for different implantation conditions is given with the aim of process development for minimizing TED. The impact of energy contamination on ultra shallow junctions is also addressed.

The Source of Transient Enhanced Diffusion in Sub-keV Implanted Boron in Crystalline Silicon

2000 ◽  
Vol 610 ◽  
Author(s):  
E. Napolitani ◽  
A. Carnera ◽  
V. Privitera ◽  
E. Schroer ◽  
G. Mannino ◽  
...  
Keyword(s):  
Surface Layer ◽  
Annealing Temperature ◽  
Crystalline Silicon ◽  
Point Of View ◽  
Low Energy ◽  
Implantation Energy ◽  
Enhanced Diffusion ◽  
Decay Constants ◽  
Transient Enhanced Diffusion ◽  
Activation Annealing

AbstractThe transient enhanced diffusion (TED) during activation annealing of ultra low energy implanted boron (0.5 keV & 1 keV, 1×1013/cm2 & 1×1014/cm2) in silicon is investigated in detail. Annealing in the temperature range from 450°C to 750°C is either performed directly after implantation or after the removal of a surface layer before annealing. The kinetics revealed two regimes of enhanced diffusion ruled by different decay constants and different activation energies. The dependence of these two processes on implantation energy and annealing temperature is described and explained from the microscopical point of view. The annealings performed after surface layer removal, revealed that the defects responsible for the faster diffusion are located deeper than the defects responsible for the slower process.

Ultra Shallow Junction Formation by B+/BF2+ Implantation at Energy of 0.5 KEV

1998 ◽  
Vol 532 ◽  
Author(s):  
M. Kase ◽  
Y Kikuchi ◽  
H. Niwa ◽  
T. Kimura
Keyword(s):  
Junction Depth ◽  
Shallow Junction ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Junction Formation

ABSTRACTThis paper describes ultra shallow junction formation using 0.5 keV B+/BF2+ implantation, which has the advantage of a reduced channeling tail and no transient enhanced diffusion. In the case of l × 1014 cm−2, 0.5 keV BF2 implantation a junction depth of 19 nm is achieved after RTA at 950°C.

Effects of Carbon Co-Implantation on Transient Enhanced Diffusion and Performances of the Phosphorus Doped Ultra-Shallow Junction Nano NMOSFET

2013 ◽  
Vol 284-287 ◽  
pp. 98-102
Author(s):  
Hung Yu Chiu ◽  
Yean Kuen Fang ◽  
Feng Renn Juang
Keyword(s):  
Cmos Technology ◽  
Shallow Junction ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Technology Applications ◽  
Implantation Process ◽  
Phosphorus Doped

The carbon (C) co-implantation and advanced flash anneal were employed to form the ultra shallow junction (USJ) for future nano CMOS technology applications. The effects of the C co-implantation process on dopant transient enhanced diffusion (TED) of the phosphorus (P) doped nano USJ NMOSFETs were investigated in details. The USJ NMOSFETs were prepared by a foundry’s 55 nano CMOS technology. Various implantation energies and doses for both C and P ions were employed. Results show the suppression of the TED is strongly dependent on both C and P implantation conditions. Besides, the mechanisms of P TED and suppression by C ion co-implantation were illustrated comprehensively with schematic models.

Rapid Thermal Processing and The Quest for Ultra Shallow Boron Junctions

1986 ◽  
Vol 71 ◽  
Author(s):  
Tom Sedgwick
Keyword(s):  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Attractive Potential ◽  
High Activation ◽  
Shallow Junction ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Diffusion Effects ◽  
Junction Formation ◽  
Short Time

AbstractRapid Thermal Processing (RTP) can minimize processing time and therefore minimize dopant motion during annealing of ion implanted junctions. In spite of the advantage of short time annealing using RTP, the formation of shallow B junctions is thwarted by channeling, transient enhanced diffusion and concentration enhanced diffusion effects all of which lead to deeper B profiles. Channeling and transient enhanced diffusion can be avoided by preamorphizing the silicon before the B implant. However, defects at the original amorphous/crystal boundary persist after annealing. Very low energy B implantation can lead to very shallow dopant profiles and in spite of channeling effects, offers an attractive potential shallow junction technology. In all of the shallow junction formation techniques RTP is required to achieve both high activation of the implanted species and minimal diffusion of the implanted dopant.

Transient enhanced diffusion without {311} defects in low energy B+‐implanted silicon

1995 ◽  
Vol 67 (14) ◽  
pp. 2025-2027 ◽  
Author(s):  
L. H. Zhang ◽  
K. S. Jones ◽  
P. H. Chi ◽  
D. S. Simons
Keyword(s):  
Low Energy ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion

Transient enhanced diffusion and defect microstructure in high dose, low energy As+ implanted Si

1998 ◽  
Vol 84 (11) ◽  
pp. 5997-6002 ◽  
Author(s):  
V. Krishnamoorthy ◽  
K. Moller ◽  
K. S. Jones ◽  
D. Venables ◽  
J. Jackson ◽  
...  
Keyword(s):  
Low Energy ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Defect Microstructure
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