Immersion Lithography

Immersion Lithography

Introduction

The growth of the semiconductor industry is driven by Moore’s law: “The complexity for minimum component cost has increased at a rate of roughly a factor of two per year”. Notice that Moore observed that not only was the number of components doubling yearly, but was doing so at minimum cost.
One of the main factors driving the improvements in complexity and cost of ICs is improvements in optical lithography and the resulting ability to print ever smaller features.
Recently optical lithography, the backbone of the industry for 45 years has been pushing up against a number of physical barriers that have led to massive investments in development of alternate techniques such as Scalpel, Extreme Ultraviolet and others.
Since the mid eighties, the demise of optical lithography has been predicted as being only a few years away, but each time optical lithography approaches a limit, some new technique pushes out the useful life of the technology.
The recent interest in immersion lithography offers the potential for optical lithography to be given a reprieve to beyond the end of the decade.