CEO Essays 2020_04_01

The CPU (Central Processing Unit) is a semiconductor chip, sort of electrical brain.

Imagine you put billions of transistors on a piece of silicon semiconductor stone small as a fingernail, engraving computer circuits on it in size of 3 to 4 atoms. If you put electricity to this 'stone', it can calculate billion times in a second, acting as an electrical brain of computers and smartphones. 

March 1982, in the lab of Electronics Technology Research Institute(now ETRI, Electronics and Telecommunications Research Institute), located in Gumi city, Gyeongsangbuk-do Province, I was observing the semiconductor which flashed upon me as a huge metal city, just like the Death Star of Star Wars. In this city, tens of thousands of orange-colored transistors, green-colored connectors, gold-glowing metal wires were twinkling. As I had wondering around in this dream-like, 5mm width and height, and 1mm thick metal city on my palm over several hours, I fell in love with this small-massive semiconductor chip. 

This fantastic CPU semiconductor chip, which I could see freely sitting in front of a microscope all day long, became my spring light. I would be happy to be a gatekeeper for the company if I could only work with CPU chips.

The picture above shows the 200MHz CPU semiconductor chip developed by DEC(Digital Equipment Corporation) in 1992 with a width and height of 1 cm.

• 200MHz means 200 MegaHertz, or 200 million Hertz, the speed of turning on and off 200 million times in a second). 

Pictures on the right are zoom-in of the CPU with a microscope.

Zooming in step by step from No. 1 to No. 7, you can see how the computer circuits are drawn and engraved with transistors and power lines on a semiconductor chip, in size of atoms.

If you enlarge figure 1 on the chip to the designed drawing (layout), it is figure 2, and when you look at figure 2 under the microscope, you can see the transistor in the size of 1 millionth of a meter, figure 3. Magnifying figure 3 with an electron microscope reveals a three-dimensional structure as shown in figure 4. Figure 5 is a vertical section of a 1mm thick semiconductor. Figure 6 is a magnification of figure 5. The part of the insulating film that looks slightly darker between the white line below in figure 6 could be observed with atomic force microscopic, which is figure 7.  In figure 7, white round-shape materials are silicon atoms, and the part written as SiO2(silicon dioxide) in the middle is the insulating film. The current manufacture technology of semiconductors could produce this insulating film in a thickness of 2-3 atoms.