Lithographic technologies

The continual progress in VLSI device development is placing increasing demands on the lithographic technologies used for their manufacture. At the present time, almost all commercial devices are made by photolithography utilizing... 

The radiation sources employed in microlithography include conventional (>300 nm) and deep-UV (<300 nm) light, electron-beam, ion-beam and x-ray sources. By far the predominant lithographic technology is conventional photolithography which... 

The basic concepts employed in early photolithography, both in materials and processing, have been extrapolated to modern lithographic technologies including x-ray and electron beam. In the remainder of this book we will discuss in detail the fundamental principles of chemistry and physics as they apply to the design and use of resist materials. 

The goal of any lithographic technology is to produce a three-dimensional relief image whose size and fidelity match, as closely as possible, that of the image in the mask or the serial exposure beam. As we discussed in Chapter 2, pattern definition in a resist consists of two distinct steps ... 

The capabilities (or performance standards) of any lithographic technology are evaluated with respect to five major criteria ... 

Fig. 2. Evolution of lithographic technology, (a) A time line noting significant events in the evolution of lithographic technology, (b) The minimum feature...

In recent years, rapid progress has been made in lithographic technology along with a concomitant reduction in the minimun feature size. Ihe object of microphotolithography is to form high resolution resist patterns. Various techniques have been evaluated for improving the resolution of photoresist. 

Despite the considerable advances that have been made in exposure and etching systems and in the area of resist materials and processing for the various advanced lithographic technologies, photolithography continues to... 

A survey of waterless lithographic technology and of the present state of the art indicates a renewed interest in this area, even though some problem areas still exist. The long term future of this technology remains uncertain unless an ink that resists toning at moderately high temperatures can be developed. 

---