Electronics, Power Electronics, Optoelectronics, Microwaves ...

2SemiconductorManufacturingHarold G. ParksThe University of ArizonaWayne NeedhamIntel CorporationS. RajaramLucent TechnologiesBenjamin Y. ParkUniversity of CaliforniaRabih ZaoukUniversity of CaliforniaMarc J. MadouUniversity of California2.1 Processes.......................................................................... 2-1* * * *Thermal Oxidation Diffusion Ion Implantation Deposition*Lithography and Pattern Transfer New Processes2.2 Testing............................................................................ 2-17* * *Built-In Self-Test Scan Direct Access Testing Joint Test*Action Group (JTAG) Pattern Generation for Functional* *Test Using Unit Delay Pattern Generation for Timing* *Temperature, Voltage, and Processing Effects Fault GradingTest Program Flow2.3 Electrical Characterization of Interconnections ....................... 2-26*Interconnection Metrics Interconnection Electrical*Parameters Conclusions2.4 Microlithography for Microfabrication ................................. 2-56* *Introduction Photolithography Current and Future* *Trends MEMS Summary and Conclusion2.1 ProcessesHarold G. ParksIntegrated circuit (IC) fabrication consists of a sequence of processing steps referred to as unit-step processesthat lead to the devices present on today’s microchips. These unit-step processes provide the methodology forintroducing and transporting dopants to change the conductivity of the semiconductor substrate, growingthermal oxides for inter- and intra-level isolation, depositing insulating and conducting films, and patterningand etching the various layers in formation of the IC. Many of these unit steps have remained essentially thesame since discrete component processing. However, others have originated and grown with the evolution ofintegrated circuits from large-scale integration (LSI) with thousands of components per chip in the late 1970sthrough to the ultra-large-scale integration (ULSI) era of today, with billions of devices per chip. Astechnology continues to evolve into the nanometer regime, further modification of current unit-step processeswill be required. In this section, the unit-step processes for silicon IC processing as they exist today arepresented, with an eye toward the future. How they are combined to form the actual IC process will bediscussed in a later section. Because of space limitations, only silicon processes will be discussed. This is not amajor limitation, as many of the same steps are used to process other types of semiconductors, and perhapsmore than 98% of all ICs today and in the near future are and will be made of silicon. Furthermore, only thehighlights of the unit steps can be presented in this space, but ample references are provided for a morethorough presentation. The referenced processing textbooks provide a detailed discussion of all processes.2-1