This paper highlights the basic principles of rapid thermal processing (RTP) systems and the important areas of concern. The basic system characteristics, the fundamental physics involved, and the techniques for temperature measurement and control are extensively reviewed. We summarize the options currently available for 15 RTP equipment manufacturers and point out the latest developments in RTP system design and temperature measurement. Some novel options for temperature control (optical, fiber optical, and photoacoustic) are included.

The role of oxidant damage to red cells in sickle cell anaemia has been of interest in recent years. Although, available reports suggest that sickle cell erythrocytes are susceptible to endogenous free radical mediated oxidant damage there remains discrepancy in the status of antioxidant enzymes and antioxidant vitamins in these patients. In view of this, 107 cases of sickle cell anaemia (36 'SS' and 71 'AS' pattern-as confirmed by haemoglobin electrophoresis) were subjected to analysis of malondialdehyde, ascorbic acid, superoxide dismutase and albumin. The results were compared with 54 age and sex matched healthy controls. The results indicate a marked increase in lipid peroxidation and superoxide dismutase levels in both 'SS' and 'AS' types of sickle cell anaemia as compared to controls. Although no difference was observed in the levels of albumin in these groups the levels of ascorbic acid were significantly depleted in sickle cell anaemia patients. The results are indicative of enhanced lipid peroxidation along with imbalance in the pro-oxidant and antioxidant status in patients of sickle cell anaemia.

Various metallization schemes are used to provide conducting layers in IC fabrication. X-ray fluorescence spectrometry has been utilized to examine the chlorine and fluorine levels in some of these metallization schemes after patterning and etching. The metallization systems investigated include A1-Si and A1-Si-Cu, with and without TiW. The corrosion characteristics of these metallizations are found to be predominantly a function of chlorine levels. The galvanic cell effects of the Cu and TiW with A1 are not significant within the range of etch processes investigated. The effect of different in situ passivations as well as various postetch treatments are presented. The residual chlorine levels at various stages of the pattern definition process are also presented.As device geometries continue to shrink, the use of A1-Si-Cu combined with TiW is fast becoming the metallization system of choice to meet required reliability and electromigration specifications. The pattern definition of A1-Si-Cu alloys is currently done by reactive ion etching or plasma etching in chlorine containing plasmas. One of the primary concerns with this process is postetch corrosion.Postetch corrosion is believed to be due to high levels of AIC13 on the metal. AIC13 is hygroscopic and in a humid environment will react with atmospheric moisture to form HC1. This is a self-perpetuating reaction as the HC1 product can further attack A1 and produce more A1CI~, with the rate depending on the moisture content and the residual C1 level (1, 2). Chloride ions have also been reported to accelerate intergranular or pitting corrosion in bulk metals (3,4).The introduction of Cu or TiW to the A1-Si metallization system has been reported to enhance the corrosion of A1 (5-7). The suggested mechanisms are the increase in C1 levels due to the presence of the TiW or Cu and/or the galvanic cell effects of TiW or Cu with A1. It has also been suggested that the C1 and moisture levels needed to induce corrosion are much lower when Cu is present (1).In the past Auger analysis (6) has been used for the analysis of chlorine. In this paper, wavelength dispersive x-ray fluorescence spectrometry (XRF) was used to determine the chlorine and fluorine levels. XRF is an established analytical technique (8) which is used in various industries requiring sensitivities of 1014 atoms/cm 2. XRF provides the advantage of nondestructive inline measurements, with sensitivities for C1 and F in the 1013 atoms/cm 2 range (if on surface) and 10 TM atoms/cm 2 (if within the layer) for the metallization thickness considered.This paper discusses the effects of chlorine levels on corrosion for an Al-l%Si-2%Cu on 10%Ti-90%W metallization scheme used in a double metal submicron CMOS process. It also correlates the magnitude of the galvanic cell corrosive effects of both the TiW and the Cu. Finally, it presents an etch passivation strategy to minimize corrosion and suggests an allowable range of chlorine levels which can be tolerated on the wafer.