Outside of life (plants and animals) I find process plasmas to be the most complex and intriguing systems observed on earth. This complexity draws me to the subject. I want to develop a global understanding of the processes that make plasmas so useful and variable. All process plasmas are similar in that the plasma source, gas-phase species and surfaces interact to make the whole system. Thus, I view all process plasmas as a continuum - plasmas used for etch are in many respects the same as plasmas used for deposition and those used for implantation. Obviously this is an over simplification of the processes. For example an inductively coupled etch plasma using Cl2 as the feed gas is clearly different than a capacitively coupled deposition plasma using silane. However, there are some very similar aspects to both plasmas.
I am particularly interested in plasma-surface interactions. This is because these interactions make plasmas useful AND these interactions are little understood, even after 40+ years of research. On a technical level, one can explain the interactions as follows. Often the plasma is created and sustained through an electric or electromagnetic heating of electrons. A small fraction of the electrons gain sufficient energy to ionize the local neutral gas. In addition, these energetic electrons will dissociate and heat, often indirectly, the neutral gas. Eventually, the ions drop across an electric sheath to a surface that is in or which contains the plasma. Neutrals, both the initial and daughter species, also diffuse to these same surfaces. At this point, a wide number of chemical and physical processes can occur, with many of them occurring in combination. This includes neutralization of the ions and subsequent reflection of energetic neutrals into the gas phase. The neutrals may undergo chemical reactions which liberate new gas species, may sputter new species into the gas-phase may adsorb on the surface or may simply bounce off of the surface. All of these processes depend on the type of surface, surface conditions and the make up of the gas impinging on the surface. In most process plasmas the principal gas-phase molecules are those that have interacted with the system surfaces. Because both the ion species and the electron energy distribution are determined in part by the gas-phase chemistry present in the system, we find a strong interaction between the plasma source, the gas-phase species and the surfaces. I, and many others, have found significant evidence that this view of process plasmas is correct. (Examples of this are given in my publications.)
Such interactions will become more critical as we switch from the fairly simple chemistry used in semiconductor manufacturing to the chemistry needed for biomedical applications. This switch will result in an order of magnitude increase in feed gases (from ~10 to ~100) with the biomedical gases being more complex (from ~1-4 carbons to 4-10 carbons) and thus producing more daughter species/radical pathways.
I study these interactions through both experimental investigation and analytical models. Our analytical models have begun to provide insight into the surface processes. The models are being further refined based on studies of the complex plasma chemistry. These chemical studies have been possible in large part due to a number of diagnostics that I have developed over the years. Primary amongst them is the use of Fourier transform infrared spectroscopy for the study of gas-phase chemistry in low-pressure, high-density plasmas. In addition, I have developed two novel plasma sources in which I can readily change plasma heating (source), gas-phase chemistry and most importantly the conditions of plasma facing surfaces. As such, I have developed experimental plasma systems that are almost as flexible as the computer simulations of process plasmas being developed elsewhere.
Over the years, I have grown as a professor. One of the most important elements to being a professor is the teaching of students. As part of my desire to be a complete professor, I worked for 3 years as the chair of the EE department undergraduate curriculum committee. (I also became an ABET evaluator.) We strove to understand why some of our students were failing while others were sailing through the same classes. UTD has a wide variety of students, ranging from traditional to part time older students. At first, we thought that the range of students we were teaching might be the issue then we looked at the classes we were teaching, in comparison to those being taught at other comparable universities. All in all, we found no good reason for one group to fail while the other succeeded. This led us to look closely at WHAT we were teaching in each course and how each course was related to the previous and the next. In the end, we came up with a systematic approach to curriculum management. After we used this technique, the average student grade (GPA) in the department increased approximately 0.2 (out of 4) and the withdraw rate dropped from 4% to 2%. Needless to say, I was hooked. I now find linkage of the program specific topics to real measures of student understanding a major interest. I am convinced that we can use this to leave a lasting legacy of better engineers. I am determined to prove this point in a rigorous fashion.
I look at teaching as a multifold issue. First, I am paid to instruct students at UTD; second, I enjoy teaching; third, teaching is a wonderful opportunity to review old material or learn new material; finally, it is through teaching that I see a chance to leave a legacy to the next generation.
While I am paid to teach, I would not be a professor if I did not enjoy seeing students learn in fact this was why I left a very good industrial research position. I have strong desire to be an excellent teacher and I have tried to model my teaching style after some of the professors that I had as a student. An example of this would be Dwight Nicholson (U Iowa). At no point was his class simple he always pushed you to excel. However, despite the fact that he was busy as the department chair, Prof. Nicholson was always willing to help students who were stuck. (The other excellent professors I had had similar traits.) As such, I do a number of things. First, I push the students as hard as I reasonably can. (On average, I have found the UTD students to be highly motivated but slightly overworked, as many have full time jobs outside of school.) Second, while I have 'official' office hours, I tell my students that they are welcome to come for help any time between 8 and 5 and occasion this has been extended to nights and weekends for students with tight schedules. Many of them take advantage of this. Finally, in my class with Prof. Nicholson, I find that he insisted that I not only could 'do' homework problems but that I could understand and explain the physical picture that the equations described. I find that I am doing the same thing with my students. Finally I remember that he tried to make the class exciting. I try to do the same. Some day, I hope to be as good as an instructor as Prof. Nicholson.
In addition to my desire to be an excellent teacher, I have a desire to teach a broad variety of classes. Thus far I have taught, UG Mathematics II, UG Devices, Graduate Plasma Technology, Graduate Plasma Sciences, UG Electromagnetism I and II and Intro Fluids. I will soon add two more fluids courses to this list. Of these three, I have taught, UG Electromagnetism and the Graduate Plasma classes, on a repeated basis. I teach the plasma because it is core to my research and allows me to review things. I teach Electromagnetism because I love it and there is a dearth of professors who are willing to teaching it. (I teach Fluids in Mechanical Engineering for the same reason.) In addition to these 'standard' courses, I have also taught a short course on "Learning, Teaching and Leading". I created this course to teach Boy Scouts in Troop 1000 in Plano, TX (T1000.org). I taught this to the leadership of the troop a number of times over the 5 years I worked with them. (I now work with the local Boy Scout district council.) I have since begun teaching it to the ME freshman classes at UTD. We are trying to determine how much this course might help all of the students and if it does we will try to teach it to all incoming students. In some sense, it is this latter short course that I expect to have the greatest impact it will have changed a university and all of the students who attend it.
Like teaching, I look at service as a three-fold issue. First, I am paid to serve on committees at UTD; second, I find great satisfaction in improving the university (and my research field) and third, service provides interactions with colleagues that I might not otherwise have and thus new ways of thinking.
Like teaching, I would not be a professor if I did not enjoy the service aspect. To me service is all about leaving the world a better place then I found it. (Teaching does the same thing!) In most of my classes I give a little extra credit to students who go out and volunteer at a church, synagogue, mosque, food pantry, etc. The requirement is that they give some of their time. I want them to understand that being an engineer or scientist is really about making the world a better place.
As a professor at UTD I have been on many committees both departmental and university-wide. The one that I am most proud of is my work as the chair of the EE Undergraduate Curriculum Committee. I held that position from Jan 2006 to June of 2009. During that time, we tackled a number of issues important to the department. However the biggest thing that we have did was to produce a systematic method for control of the curriculum. With that system we have come up with approximately 200 fundamental concepts that cover all of the engineering/science courses needed for a BSEE. This systematic method lies between course level program development and "just in time" program development. (It is in fact a "systems engineering" solution to engineering education.) These fundamental concepts are all held within a single "fundamentals" chart which shows where those concepts are taught, which other classes they are used in and which courses are pre-requisites. At first, it was very difficult to get the other faculty to buy into all of the necessary work (try herding cats) however, as we progressed they have begun to view it with pride. The "fundamentals" chart is also known as the "Eye" chart as it takes an E-sized sheet of architectural paper to print and then in small print. We, the faculty, now know what we teach and how it is linked. I have used this same technique to create a map for our new Mechanical Engineering program and from this laid out the four year course sequence and timing. (In effect, I have created most of the fundamental infrastructure needed for the new department.) We, in ME, are now working to improve that original map. We expect great things. In addition, we are also using these maps in both EE and ME to help our students understand the big picture which should make them better engineers. I believe that this method has the potential to revolutionize education in the US.
In addition to my service at UTD, I am also involved in service off campus. I have done all of the standard service items including: reviewing papers, reviewing proposals, serving on society/conference executive committees (this includes AVS, GEC and new workshop series on flexible electronics that I am setting up). In each of these, I have helped to make my own field stronger and I have learned from the interactions. However, like university level committees, I have one in which I am most proud; That one was that until recently I regularly worked with a local boy scout troop which has about 100 scouts in it. Those strong interactions lasted over 5 years with me working an average of 4 to 5 hours per week with the troop. (Recently, I reluctantly had to reduce my participation because of other time pressures.) My primary job with the troop was that of scribe coach for the scouts but I also worked to help the scouts learn how to learn and from that how to teach and how to study. (In fact I put together a 4-hour class for them on the subject.) I also talked to many of them about what they wanted to do with their future. I have seen many of them go on to become successful college students. This gives me a great sense of accomplishment. In addition, I am trying to use some the things that I developed to teach the scouts to help professors at UTD become better teachers. This improvement in life and the future is why I enjoy service activities.