A further refinement in semiconductor technology is the integrated circuit. By successively depositing layers of material and etching patterns to define current paths, we can combine the functions of several MOSFETs, capacitors, and resistors on a single square of semiconductor material that may be only a few millimeters on a side. An elaboration of this idea leads to large-scale integrated circuits and very-large-scale integration (VLSI). The resulting integrated circuit chips are the heart of all pocket calculators and present-day computers, large and small. An example is shown in Fig. 44-34. The first semiconductor devices were invented in 1948. Since then, they have completely revolutionized the electronics industry through miniaturization, reliability, 0speed, energy usage, and cost. They have found applications in communications, computer systems, control systems, and many other areas. In transforming these areas, they
have changed, and continue to change, human civilization itself.