This laboratory experience is intended to help engineering students who plan either to work within the semiconductor industry or to utilize semiconductors in their designs. The latter purpose is not as obvious as the first, but knowledge of how transistors and ICs are fabricated can help an engineer get the most out of them. Modeling semiconductors as black boxes with certain specifications (SPICE models) is an important engineering technique, but after this laboratory the student will not have to treat semiconductors as mysterious black boxes.
The student will see many of the "work horse" technologies of the semiconductor industry. Although the "cookbook" nature of the lab manual threatens to trivialize the processing itself, opportunities abound to observe phenomena crucial to the industry. The student is reminded that he or she is here to learn. Observations cannot be made for the student, that part of learning requires active participation.
There has already been so much information discovered in this area (as in many others), that it is far more important for an engineer to develop skills in the acquisition of this knowledge rather than to attempt to memorize everything. These skills involve making efficient use of books, libraries, CD-ROM databases, and the wealth of information on the worldwide computer network. This laboratory experience, however, should help provide another valuable resource - personal experience. The most valuable contributions an engineer can bring to the job are human intuition, creativity and skepticism. As you make your own integrated circuits this semester, often take the time to improve your conception of what is REALLY going on in the semiconductor during the fabrication and operation of the devices by thinking about them at the lowest level you can. Visualize the nearly perfect three dimensional array of silicon nuclei and their associated electron clouds quivering because the temperature is above absolute zero. Remember to update your image periodically throughout the processing and testing of the devices. This exercise is not automatable and can help you perform mental experiments to test creative new ideas.
Skepticism is also hard to program into a computer or to learn from reading. Not all published data or conclusions can be trusted. For instance, there are plenty of published values for the work functions for silicon and aluminum which would predict that the schottky diodes you will make will turn out to be resistors instead. There are also contradictory explanations in the literature for why silicon oxidizes faster in steam than in dry oxygen. Sometimes there is no substitute for actually doing something. Try to keep your curiosity high and your eyes wide open as you make your own ICs from scratch and, hopefully, you'll have fun too.