APPLICATIONS OF TECHNOLOGY:

	GENERIC DIAGRAM OF THE BERKELEY LAB PLASMA IMMERSION ION IMPLANTATION SYSTEM

• Conformal doping of 3-D nanoscale structures
• Tilt-angle ion implantation
• Pulsed electron annealing of semiconductors
• Creating multi-layer EUV mask coatings

ADVANTAGES:

• Generates uniform plasma density around 3-D micro and nanoscale features
• Achieves shallow implantation while preserving high ion flux and throughput rates
• Eliminates the problem of electrical charge build-up on specimen during annealing
• Produces plasma free from unwanted impurities
• Implantation time is independent of wafer area
  

ABSTRACT:

Scientists at Berkeley Lab have developed a plasma immersion ion implantation (PIII) system designed to solve plasma density and conformity problems associated with 3-D doping at nanoscale dimensions. It also enables the use of plasma immersion for tilt-angle ion implantation.

Progress in producing smaller semiconductor device geometries depends on achieving shallow ion implantation while preserving high ion flux rates, throughput, and implantation uniformity. The Berkeley Lab PIII system developed by Ka-Ngo Leung and colleagues enables implantation at ultra-shallow depths with high dose rates on large diameter wafers. The multicusp ion source design results in constant field strength contours and delivers plasma density with less than one percent variation.

The Berkeley Lab system makes use of RF induction plasma generation that doesn’t produce cathode materials like tungsten which could lead to low-level implanted impurities. The implant ion dose rate is easily controlled, so the target won’t overheat. Fine detail on the target is retained because voltage breakdown conditions are controlled.

The Berkeley Lab PIII system can also incorporate a plasma ion source of boron, arsenic, or phosphorous that is essentially free of unwanted hydrogen, carbon monoxide, carbon dioxide, and water ions. This component makes use of the different ionizing potentials of materials to deliver pure plasmas.

STATUS:

• U.S. Patent #5,558,718 and #5,517,084
• Available for licensing or collaborative research. The Berkeley Lab PIII system is based on two issued patents and one patent pending.

REFERENCE NUMBER: IB-1725, IB-993, IB-952

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• RF-Driven Plasma Source for Ion Implantation
• Selective Ion Source for Semiconductor Devices