Semiconductor Basics

15The Future

OBJECTIVES OF THIS CHAPTER

Predicting the future is always problematic. Someone said that the probability of being right is always 50%: I am either right or wrong, either yes or no, I win or I loose. In spite of that, I will attempt to give you an idea of progress in semiconductor technology and some of the thoughts engineers have about the future.

In the 1960s the first silicon wafers fabricated were about 1 in. or 25 mm in diameter. Now we are already using 300 mm wafers, about a foot in diameter. Considering that the area is proportional to the square of the radius, we are talking about an increase in area of almost 150 times. Can we increase this further? Yes, companies are now working to develop 450 mm wafers. This increases the area by another factor of 2.25. This increase will make the die cheaper but the investment (developing the technology and modifying all the process equipment to accommodate the larger wafer size) is enormous. This, by itself, may be an improvement in the cost of the chips but not in their performance. Furthermore, the larger the wafer the higher the probability that there may be errors and defects, which will make the chips not as cheaper as we may expect.

15.1 The Past

As historians like to say, we can learn about the future by looking at the past. So, let me review what has happened in the past.

• 1900s: Development of the first vacuum tube, the triode, and the beginning of the electronic age. The feature size (by feature ...