The post on Processors & Microfabrication was a brief but helpful refresher on the current state of the art in microfabrication. I have found some (more current) interesting videos on chipmaking this past week. After reviewing an introduction to manufacturing, I found myself wondering which area of manufacturing would be interesting to me (one of the chapters had a question like that). It hit me that fabs are the only manufacturing industry that seem really intriguing at this point (perhaps based on my background in computer science). Therefore, I have been trying to get up to speed with what’s happening in semiconductor manufacturing.
The first video on chipmaking in TX gave me a good sense of how many companies are in this space. Learning that the integrated circuit was invented at Texas Instruments leaves me surprised at how little I know about the history of chips. Some of the companies manufacturing chips in TX are Samsung, Texas Instruments, Infineon, Global Wafers, NXP, and Applied Materials. TI mentions their Power management solutions as part of the vast reach of their products. The video highlights the importance of space, power, and water.
The next video is yet another overview of semiconductor manufacturing. One of the key takeaways for me is that Taiwan leads not just in logic (CPUs, GPUs, etc) but also in memory, courtesy of Micron! 25% of Micron employees are in Taiwan, producing 65% of Micron’s DRAM!
Inside Micron Taiwan’s Semiconductor Factory | Taiwan’s Mega Factories Ep.1
One of the key lessons from reading about oxidation was that Si has a key advantage over other semiconductors – it oxidizes much more readily thereby simplifying the development of insulation. I was looking up videos on the Deal-Grove oxidation model law when I stumbled into these videos by Chris Mack from a microfabrication course at the University of Texas at Austin using the same Microfabrication book I’m reading! It’s amazing how much free content there is out there.
Diffusion is a key step in wafer processing for microprocessor manufacturing. Fick’s laws are therefore an important component in understanding diffusion. Fortunately, there are great resources online for an overview of Fick’s law. I started with the Khan Academy video on Fick’s law of diffusion (embedded below). It was informative but did not go into the level of detail I had hoped for.
Some digging around led to a series of lectures from the Mechanical Engineering’s Fertig Research Group at the University of Wyoming. This video on the mathematics of diffusion (Fick’s 1st law) was the level of detail I was hoping for and was therefore a good supplement to the Khan Academy diffusion overview.
And here’s the video on Fick’s 2nd law (again showing how to derive it and some brief comments about PDEs). I wonder if there is some accessible visualization that could be done of various solutions to the diffusion PDE.
Crystal defects play an important role in semiconductor fabrication. One type of defect is a Frenkel defect. Understanding such defects involves determining the vacancy concentration as given by Arrhenius function. I reviewed several videos to help me understand this equation:
Background Concepts
I took a detour to remind myself about activation energy, electron volts, and Boltzmann’s constant (all of which feature when studying Arrhenius function).
Line Defects
Another type of crystal defect is a line defect, e.g. edge dislocation. These videos contain additional information about edge dislocations.
Area Defects
A stacking fault is an extra plane of atoms. Some resources about stack faults:
Gettering is a process by which impurities and defects diffuse through the crystal (controlling where defects occur). This can be used to improve yield in semiconductor manufacturing as explained in this video:
The previous post outlined my introduction to materials science with interest stemming from applications in microfabrication. Reading section 2.2 of Fabrication Engineering at the Micro- and Nanoscale left me curious for more information about crystal structures. A YouTube search for “face centered cubic structure” led me to the videos below, which proved sufficient for gaining a basic understanding of crystal structures.
These are also discussed in section 2.2 of the text and are explained in these videos. Interestingly, neither of the videos mentioned the fact that the plane notation also denotes a vector (from the origin) that is perpendicular to that plane!
An important concept when working with materials is how to represent their properties. Phase diagrams are often used for this. I have found watching lectures to be an easier way of getting into a field as new (to me) as microfabrication. This Intro to Phase Diagrams {Texas A&M: Intro to Materials} video, for example, was an easier introduction to the topic than the notes in the microfabrication book I was reading.
This video was also my first introduction to the types of issues studied in the materials science space. The next topic in the microfabrication book I was reading was crystallography. I wanted to get an overview of the area before delving into the microfabrication aspect of crystallography. A YouTube search led me to this Lecture – Intro to Crystallography from my alma mater (interestingly, from the materials science department again)!
After watching these videos, I did a quick search for material science in the Amazon books section, hoping to see the types of topics people study in this field. Materials Science and Engineering: An Introduction looks like a great candidate (cost aside)! Looks like this is an area folks in semiconductor manufacturing need to have a handle on… More to come on crystallography as it pertains to semiconductors.