The objective of this research is to enhance fabrication of devices based on compound semiconductors in areas related to energy, nanoelectronics and nanophotonics. The approach is to acquire one inductively coupled plasma (ICP) reactive ion etcher (RIE) for etching compound semiconductors and materials on compound semiconductors to augment the tool set available within the shared-access University of Texas at Dallas (UTD) shared-access Cleanroom Research Laboratory (CRL).
Intellectual Merit: The project will close the gap in compound semiconductor applications, unify research and development in materials and devices, and allow teaming among university and industry researchers for a wide variety of application segments including communications, military, medical and energy.
Broader Impact: The UTD CRL enables the research of over 160 users throughout UTD as well as academic researchers from other universities. Hands-on experience with state-of-the-art equipment prepares students and post-docs to enter the workforce ready to engage in research, development, and manufacturing. The breadth of functionally diverse materials, structures and devices enabled by this RIE will attract a broader pool of researchers beyond the current user base. The PIs will develop a two lecture sequence for an undergraduate Nanotech Instrumentation course which will focus on facilitization of advanced research equipment using this new RIE as the example. This represents a unique opportunity to directly show undergraduates how numerous disciplines are required to manufacture, install and operate advanced research equipment.
The University of Texas at Dallas (UTD) was awarded funding by the NSF to equip its Cleanroom Research Laboratory (CRL) with a state of the art reactive ion etch (RIE) capability for compound semiconductors and materials. In order to process a wide range of functionally diverse materials, we procured one Plasma-Therm Versaline etcher with 8 gas inputs. The cleanroom user committee convened a meeting in November of 2010 to discuss the detailed specifications to ensure that the appropriate capabilities were procured. The Inductively Coupled Plasma (ICP) RIE is the same model and configuration of the existing RIEs for silicon-based substrate processes which dramatically simplifies process development, equipment maintenance/repair, and user training. The system includes a load-lock and process chamber which can process wafers from pieces (using a carrier wafer) up to 200 mm, a 60/600 W 13.56 MHz RF bias power package, a 2.5 kW 2 MHz ICP RF power package, Windows XP computer control, and associated pumps, gas lines, electronics, etc. This reactive ion etcher is able to etch numerous compound semiconductors (e.g. InxGa1-xAs, AlGaAs, InP, InSb, GaN), metals, and dielectrics using numerous etching gases (Cl2, BCl3, HBr, CH4, SF6/CHF3, H2, N2/O2, Ar/He). The plumbing of numerous gases provides for a very flexible system which can etch numerous materials with different etch profile characteristics. The system was ordered by UTD in November, 2010 and the system was delivered in July, 2011. The new RIE was placed in the Metallization/Plasma Etch Bay of the UTD CRL. In order to prepare the laboratory for the new RIE, a variety of fit-out activities occurred. UTD purchased a new SDC gas cabinet for CH4 and HBr that was placed in the CRL gas storage bunker. UTD also contracted SDC to modify existing gas cabinets (Cl2/BCl3/H2) with additional gas sticks for the new etcher. Midas gas sensors, heater jackets for gas lines and gas regulators for non-toxic gases were procured by UTD. Finally, TDIndustries was contracted to fit-out utilities for the system including electrical, exhaust, gas lines, vacuum, water, gas cabinets, and fire, life and safety systems as described in the attached quote. System installation and connection was completed in August, 2011. Following initial testing, the system was made available to the general CRL user base beginning in mid-September, 2011. Since that time, researchers have been actively using the RIE to perform cutting edge research in advanced nanoelectronic technology and energy harvesting. For example, the fabrication of GaN HEMT devices, InGaAs FinFETs, and multijunction photovoltaics have been enabled by the new RIE. These activities, and the presence of the tool itself, has helped UT-Dallas faculty in obtaining external research funding for through Texas Instruments, Inc., the Semiconductor Research Corporation, and the Air Force Office of Scientific Research. Additionally, pending and future proposals (NSF, DOE, SRC, AFOSR, AFRL, DARPA, Applied Materials, Texas Instruments, Raytheon) have been enabled and strengthened due to the presence of the RIE. As a result, student and post-doctoral education has been significantly enhanced and numerous publications and conference presentations will result in the near future. One of the primary goals for broadening the impact of this MRI acquisition was the development of lectures which focus on facilitization of advanced research equipment using these new RIEs as the example. We expanded this goal by initiating a small Independent Studies course during the Spring of 2011 supervised by Prof. Eric Vogel entitled, "Facilitization of Advanced Semiconductor Equipment." Two undergraduate students took this course. Every two-three weeks, the students were required to give a presentation on a topic related to the Reactive Ion Etcher: RIE System Design Including Facilities Requirements, Vacuum Equipment Technology/Fundamentals of Gases, Semiconductor Devices, Semiconductor Processing, Plasma Chemistry, Plasma Etching and RIE of III-V semiconductors. The audience for these technical presentations included experts (Prof. Vogel, other Professors, graduate students, cleanroom manager and staff) in each of the areas. Prof. Vogel and cleanroom staff met with the students every week and gave only general guidance as to what should be included in the next presentation. The primary guidance was that the presentation should link the technical content to the facilitization and use of this new RIE. The final presentation, as well as the other 6 presentations prepared by the students, can be used in the UTD Introduction to Nanotechnology class to explain the complexities associated with facilitization of advanced semiconductor equipment. The students also travelled to St. Petersburg, FL with cleanroom staff to do acceptance testing at the facility. The students were given a tour of the facility and learned how the RIE is manufactured.
