Marvin Farley

Wafer charging and beam interactions in ion implantation

Abstract Ion implantation into insulating layers results in an accumulation of surface charge. If this charge is excessive, microscopic but easily observed punch through craters can be produced. In addition, wafer charging can result in non-uniform implants. The effect is particularly insidious because monitor wafers without insulating layers will show no effect while adjacent product wafers with photoresist or oxide coatings may show gross non-uniformities. Well designed electron flooding will relieve both effects.

A high-current ion implanter system

Abstract The important issues in the design and development of the Eaton NV20A high-current ion implantation system are discussed. The control system is based on a Sun Microsystems workstation connected through an Ethernet to a multiprocessor controller. The software is based on an object-oriented environment with a layered operator interface design. An adaptive robotics-based wafer handling system, and clampless wafer holding allow for high throughput with good particulate performance. The modular design of the beam optics add to system versatility.

In-situ Rutherford backscattering design for early SIMOX-SOI metallic screening

Abstract Design and implementation is described of an in-situ, real-time Rutherford backscattering spectroscopy system for SIMOX-SOI impurity monitoring during SIMOX-SOI processing. The prototype instrument utilized an existing high-current, 65 keV oxygen beam as the primary source together with a spherical electrostatic analyzer for detecting the backscattered ions. Distinct elemental edges were found at predicted spherical analyzer voltages for pure metal samples of Mo, W, Cu and Au. Thickness and concentration measurements on thin samples of stainless steel of Ta, Mo, Cr, and Cu were also performed. The concentration of the layers with respect to the silicon substrate were precisely calculated by comparing the measured signal strength to the theoretical value. There are plans to incorporate such detection systems onto a SIMOX-SOI production implanters in the near future.

Applied Quantum X Implant System: Technology Enhancements to Enable Production‐Worthy Performance at the 45 nm Node

Mechanical scanning of the wafer in 2 dimensions is one approach that has been used to achieve single wafer processing for high current ion implantation. This approach simplifies the beamline design, compared to scanned beam or ribbon beam architectures, but has required a number of new technologies and methods in the scanner hardware and in dosimetry control. The Applied® Quantum X Implant system was designed to incorporate these new technologies, and has achieved the process performance and low energy productivity required for advanced junction formation at the 65 nm technology node. Since its introduction, extensive qualification and development work has been carried out, to extend its capability to the next technology generation. A number of further innovations and improvements to the beamline and platform have been developed, extending its throughput and process control capability to be production‐worthy at 45 nm.This paper will review the process control challenges associated with the 2d mechanical ...

Performance characteristics of the NV-20A high current ion implantation system

Abstract High current ion implantation systems are now widely used in the manufacture of VLSI and ULSI devices. As device designs become more complex and diverse, the demand for tighter process control in the implanter also increases. Sensitivity to subtle contamination levels, particles, charging stress, energy variations, and other undiscovered causes continue to emerge as temporary limitations to device manufacturing technology. Continuous improvement programs are now a way of life for the equipment supplier. The large parameter space requiring evaluation and the limitations of much of todays metrology require that sophisticated statistical techniques be utilized in designing experiments and analyzing the results. This paper summarizes the process and performance measurements taken as part of a continuous improvement program for the Baton NV-20A high current implantation system. The results of designed experiments and the subsequent equipment and process modifications are presented for the following areas: dose control, wafer charging, cross contamination, and equipment reliability.