Cesar Garza, Principal Engineer
- Samsung Semiconductor
- Ph.D., Physical Chemistry, Texas Christian University, Fort Worth
César Garza’s career started in Mexico and has crossed the border several times as it matured. Garza says he started school as a young dreamer who wanted to use chemistry and physics to really “understand how the world worked from first principles.”He first studied phytochemistry, the chemistry of plants, during his undergraduate time in Mexico, then completed his Ph.D. in the U.S. in physical chemistry. Back in Mexico, he went to work with Kodak making photographic film, before returning to the States to work with Texas Instruments in R&D. There he was part of a team that developed the process for the next generation of semiconductor devices using optical lithography, a process used to print patterns on computer chips that Garza says is very similar to the photographic process he learned at Kodak.
Though his career has spanned countries and industries, ACS, “has been a life-long source of professional development and learning,” says Garza. “There are plenty of opportunities [within ACS] for going deeper in my field of expertise, but just as important, it is a very good source to learn about related science fields.”
Today Garza is a Principal Engineer with Samsung Semiconductor and fabricates computer chips for the wireless industry.
At Samsung, we make state-of-the-art computer chips for the wireless industry. These are the types of chips that go into cellular phones and tablets. The factories used to make these chips are called fabs and are very expensive to build. The typical cost of one of these fabs is in the neighborhood of $5 billion. The computer chips are classified according to their design rules, which roughly correspond to the transistor or minimum features used to make the chip. According to the ITRS (InTernational Roadmap for Semiconductors) the design rules in high-volume production have a pitch of 28 nm; 20 nm is being prototyped. The minimum features are 10-14 nm wide; this is very challenging. One must maintain a high level of productivity and yield to justify the high cost of the equipment on processes that are very complex. In some instances, one is almost controlling processes at the atomic level.
Following the ITRS roadmap, new technology is introduced every 2 years, and my job is to help set up the new technologies that enable this. My job is also to be a resource when the first and second responders have not found a solution when a problem arises. Problems always arise, and we must quickly find a solution that is effective. This is a very fast-paced, multidisciplinary environment, where I work with experts in other disciplines like electrical, chemical, mechanical and computer engineering.
For example, optical microlithography is the technology used to print a pattern on a photosensitive polymer called photoresist. A schematic representation is shown below for further clarity
For instance, if the features are 14 nm wide, the variation of the pattern needs to be maintained within 10%. This is 1.4 nm, very close to the size of a chemical bond! And this needs to done thousands of times on a daily basis. When this does not happen, we need to understand the cause of variation and put a fix in place in a short time.
Another problem related to the size of the features is related to the pattern fidelity: Any sort of contamination will distort the pattern and may make the chip fail. These are called “defects” in our lingo. These defects can be as small as a few nanometers, and understanding the source of the contamination is very challenging. The materials that are used are purified to single parts per billion. In addition to that we monitor the purity of all the materials that are used in the manufacturing process.
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The manufacture of computer chips is completely automated. A variety of programs developed internally, most of them Web-based, are used to collect data from the factory and direct experiments. My company's own version of Outlook is used to communicate internally and externally via e-mail. Finally, we also use several commercial computer simulation programs. I can’t specify the vendors to avoid giving the impression that we endorse a particular vendor over another. However, some examples are Prolith from KLA and Sentaurusfrom Synopsis .
The environment is very fast paced but informal. My primary work area is a cubicle in an office area. The actual manufacturing of the chips is done in the clean room. As its name implies, this is a very clean manufacturing environment, because any kind of foreign matter that falls on a chip will kill it. All processes and movement of material is computer automated. I go there, but for the most part I can access most of the data I need from my computer in my cubicle. When I go to the clean room, I have to follow a strict protocol and use special protective clothing that completely covers me to avoid bringing external contaminants to the fab.
There is a lot of open space in the office area, and people interact informally with each other very frequently. We do have formal meetings to review data and make decisions. Each room has lots of computers and very large displays for all to see the data and presentation material.
My typical work week is 70 hours. Not everyone works these hours but I enjoy my work. For the most part, I don’t travel for work. When I do it tends to be for extended periods of time ranging from a couple of weeks to several months. The travel involves going to Samsung advanced research facilities in Korea.
Get a good night's rest. I also exercise frequently in the gym we have at work. I also routinely go for a little walk every day to reflect on the problems of the day. It can be as short as a few minutes or as long as 15 minutes. I find it helps me think and put things in perspective.
I’m very fortunate in that I have had advice from very good people. If I had to choose one, I would chose the advice from my father, who said I was free to choose whatever field I wanted to make a living. There is no shame in any honest living, but it is a shame not trying to be the best one in your chosen profession.
I treat people with respect. I appreciate the effort and dedication they put into their work, regardless of their level in the organization.
Understanding how important relationships are in getting things accomplished. One can demand that things get done, but in today’s environment people are overburdened. People will stretch to help a friend but not a stranger.
Chemical & Engineering News. I like to keep up with advances in diverse fields.
I treat people with respect. I appreciate the effort and dedication they put into their work, regardless of their level in the organization."