Moore's Law, a prediction first made in the 1950's, states that the number of transistors packed on computer chips will double about every 18 months, bringing faster, cheaper computers. The prediction has more or less held true, but the rate of development has begun to slow, down to about a doubling every 23 months. And engineers have seen on the horizon the day when it just isn't possible to keep pace with the law any longer.

Two recent announcements have made it possible to keep up with Moore's Law - and may allow the development of new chips to proceed even more quickly than Moore's law predicts. Last week, the Intel Corporation announced that it had developed a new way to pack more data into the circuits on board its flash memory chips. Not to be outdone, just days later IBM researchers announced that they had discovered a method for wiring computer chips with copper instead of the traditional aluminum. The two announcements may mean that the price of powerful, high-speed computing will soon be on the way downward.

Once upon a time, transistors in flash memory chips (the kind that can retain information even when power to the chip is not flowing) could only exist in one of two states - either with or without a charge. Intel scientists have developed a method that lets them store and detect fractional charges in the transistor. Rather than reading a transistor as empty or full, flash memory units of the new design can read a circuit as empty, one-third full, two-thirds full, or completely full. Having four possible states to choose from makes it possible to pack twice as much information into a chip containing the same number of transistors. And Intel says that it may very well be possible to store and sense even smaller fractional charges, thus storing more and more information in the same space. Intel engineers project that come 2001, prices for flash memory could drop as low as a $1/megabyte, down from today's prices of $15-20/megabyte.

The IBM advance is perhaps even more significant, affecting chips of almost every design. It allows chipmakers to wire chips with highly conductive copper instead of more resistant aluminum, speeding the electric flow along the connections within tiny circuits. Chipmakers have wanted to use copper, one of the best conductors, for a long time, but technical problems with copper-based chips have stumped developers until now. Copper can "poison" the silicon-based transistors, and is also difficult to get to stick to silicon chips, so chipmakers have been using aluminum wiring instead. But as chips get smaller and circuits get more tightly packed, working with aluminum becomes less and less efficient. IBM developed a way to insulate the silicon from the copper layers - an advance that they say will increase chip speeds by 20-40% and make chips cheaper as well.

In this segment of Science Friday, we'll take a look at these recent advances, talk about what they mean for the future of computing, and take a look down the road to see what might be around the corner.