| Chemical mechanical planarization, or CMP, has become one of the newest and most important fabrication technologies adopted by the semiconductor industry worldwide, despite a remarkably nontraditional and somewhat controversial developmentalhistory. Begun as a mere research and development curiosity more than 20 years ago at IBM, the technique borrows heavily from the traditional mechanical wet polishing processes for silicon substrate wafers and optical glass lenses. Introduced for production at a time when dry fabrication processes were overwhelmingly favored, the completely wet CMP process was initially considered unconventional and incompatible with the rest of the manufacturing processes, to say the least. In addition, to an industry that is meticulously conscientious about particle contamination, a process that intentionally uses slurry saturated with particles seemingly adds insult to injury and thus qualifies as a true disruptive technology. This was well before the world became familiar with such a catchy yet descriptive term ‘‘disruptive technology’’ popularized through a series of articles and books by renowned Harvard Business School Professor Clayton Christiansen on innovations in commercial enterprises. Some examples of his works include Disruptive Technologies: Catching the Wave, coauthored by Joseph L. Bower, Harvard Business Review, January–February 1995 and The Innovator’s Dilemma: When New Technologies Cause Great Firms to Fail, Harvard Business School Press, 1997. Like many other major disruptive technologies seen by society throughout history, CMP indeed has lived up to its reputation. It disrupted the conventional thought process but enabled an industry to overcome many technological challenges, significantly advanced the processing capability for ever diverse and complex semiconductor devices, and inspired innovations in several associated fields such as wafer cleaning, defect inspection, and complex chemical delivery. |
