Search

Mathematical models of semiconductor processes are heavily used within the microelectronics manufacturing industry. They are used to design and understand molecular-level effects, comprehend and develop local patterning processes, and modify the design pattern to better image the desired pattern on a wafer. To accomplish these tasks, different model types are developed including molecular models, bulk models, and compact models. All models and model applications must resolve the interaction between the competing effects of model computation time and model accuracy. This chapter discusses the basics of mathematical models used for optical, EUV, and e-beam lithography modelings.

Publisher Summary This chapter discusses the pathogenic role for leukotrienes (LTs) in the lesser explored areas of disease. This perspective is limited to those LTs (5-HETE, LTB, LTC, LTD4, and LTE) that are synthesized from arachidonic acid (AA) via the 5-lipoxygenase (5-LO) pathway. In a study of 8 cluster headache patients, plasma levels of LTB4 have been found to be significantly elevated during an attack compared to the symptom-free periods. More recently, it has been reported that LTC 4 is detected in the plasma of migraine patients during the prodromal phase and in greater amounts during the beginning of the attack phase. Recent evidence strongly implicates LTs as significant factors in the pathophysiology of anaphylactic, endotoxic, and traumatic shock. In the presence of antihistamines, the selective 5-LOIs has been found to effectively block the ovalbumin-induced drop of coronary flow. Evidence, implicating the involvement of LTs in diseases of the kidney, has been discussed in the chapter. The most frequently mentioned renal disease suspected of being at least partly LT mediated is human glomerulonephritis. The upper gastrointestinal effects of LTs have been briefly described. Infusions of LTC 4 or LTD 4 significantly and dose-proportionally reduced gastric blood flow, gastric mucosal blood flow, gastric oxygen consumption, and acid output. The development of second generation 5-lipoxygenase inhibitors and antagonists of LTB 4 , LTC 4 , and LTD 4 , with extremely enhanced potency and selectivity, offers the promise of new insights into the contributions of leukotrienes to the pathophysiology of these diseases.