Michael D Johnson

Title: Michael D Johnson: Innovator in Ion Source Technology

Introduction

Michael D Johnson is a prominent inventor based in Peabody, MA (US), known for his contributions to ion source technology. With a total of 5 patents, he has made significant advancements in the field, particularly in the area of ion implantation systems.

Latest Patents

One of Johnson's latest patents is for a dual cathode ion source. This innovative ion source features dual indirectly heated cathodes that can be independently biased relative to their respective filaments. This design allows for the variation of the beam current profile extracted from the ion source. In certain applications, this ion source is utilized in conjunction with an ion implanter, which includes a beam profiler to measure the current of the ribbon ion beam based on beam position. A controller uses this data to independently adjust the bias voltages of the two cathodes, enhancing the uniformity of the ribbon ion beam. Additionally, the current through each filament can also be controlled independently.

Another notable patent involves ion beam quality control using a movable mass resolving device. This system optimizes a ribbon ion beam in a beam line implantation system. It includes a mass resolving apparatus with a movable resolving aperture, allowing for adjustments in both the X and Z directions. The controller can manipulate the mass analyzer and quadrupole lenses to move the crossover point of desired ions, thereby affecting the parameters of the ribbon ion beam to achieve specific results.

Career Highlights

Michael D Johnson is currently employed at Varian Semiconductor Equipment Associates, Inc., where he continues to innovate in the field of semiconductor equipment. His work has significantly impacted the efficiency and effectiveness of ion implantation processes.

Collaborations

Throughout his career, Johnson has collaborated with notable colleagues, including Bon-Woong Koo and Frank Sinclair. These partnerships have contributed to the advancement of technology in their field.

Conclusion

Michael D Johnson's contributions to ion source technology and his innovative patents reflect his expertise and dedication to advancing the field. His work continues to influence the development of ion implantation systems, showcasing the importance of innovation in technology.