Plasma Etching...

Image from Black Inventors

Plasma etching utilizes a gas excited/ionized in an electromagnetic field into a plasma - the fourth state of matter (solid, liquid, gas, plasma). Etching is how the semiconductor industry transfers a pattern in a photomask (a designed chrome mask) using UV light and photoresist. The resist captures the pattern, and is developed like photos (in old-style film and a camera). The plasma uses physical as well as chemical processes that react with the film to remove it leaving the exposed pattern. The resist is usually stripped away before subsequent processing in the wafer fab.

Plasma etch is used to transfer that pattern (s) becoming the integrated circuits in your cell phone; remote control; your thermostat in your home; your security system; your laptop; its mouse, servers for banks and the Internet: basically everything electronic you can think of.

You have the genius of this man to thank for it:

Physicist George Edward Alcorn, Jr. is best known for his development of the imaging x-ray spectrometer. Born on March 22, 1940 to working class parents, Alcorn was an excellent student and star athlete. He was awarded an academic scholarship to Occidental College in Pasadena, California, where he completed his B.A. in Physics in 1962. From there, Alcorn pursued graduate studies at Howard University in Washington, D.C. He earned his master’s degree in nuclear physics in 1963, and his Ph.D. in atomic and molecular physics in 1967.

At NASA Alcorn developed the imaging x-ray spectrometer. An x-ray spectrometer assists scientists in identifying a material by producing an x-ray spectrum of it, allowing it to be examined visually. This is especially advantageous when the material is not able to be broken down physically. Alcorn patented his “method for fabricating an imaging x-ray spectrometer” in 1984. He was cited for his method’s innovative use of the thermomigration of aluminum. For this achievement he was recognized with the NASA/GSFC (Goddard Space Flight Center) Inventor of the Year Award.

Alcorn is credited with more than 20 inventions, and holds at least eight U.S. and international patents, many of these related to the semiconductor industry. For instance, he developed an improved method of fabrication employing laser drilling, and a process for improving the process of plasma etching.

MIT Inventors of the week: George Edward Alcorn, Jr. PhD
Plasma Etching: Dr. Lynn Fuller, RIT