关键词：电子信息；半导体；拉曼成像；微电子材料
摘 要：The unique versatility of micro-Raman spectroscopy (μ-RS) in semiconductor physics remains in Raman imaging. Numerous applications cover the whole development of modern electronic and optoelectronic devices: from semiconductor growth to advanced device inspection tools. In this chapter, a wide variety of semiconductors (SiC, graphene, GaN, GaAs, SiGe, strained Si, sSOI, SGOI) and devices (FETs, lasers, MEMS) are addressed. First, it will be shown how Raman mapping enables to check the crystalline quality, the composition, the doping, and the uniformity of as-grown semiconductors. Then, we will focus on the most popular application in microelectronics: strain measurements either at the device or at the full wafer scale. Finally, we will show how μRS imaging can be used for final device inspection through the temperature mapping of operating devices (FETs, lasers, actuators). Since the first report by Raman in 1928 [1, 2], Raman spectroscopy has become increasingly popular in materials science and, especially, in semiconductor physics and microelectronics. Basically Raman scattering probes the inelastic scattering of a monochromatic light (incoming-photons) by the atomic vibrations in a medium (solid, liquid, or gas). In crystalline solids, the atomic vibrations are quantized (phonons) and they are very sensitive to internal and external perturbations, such as doping and stress. The frequency of the scattered light (out-coming photons) is then a local probe of the perturbation experienced (or not) by the medium. Today, the large number of results collected on semiconductors, combined with a good theoretical understanding of the scattering mechanisms, allows to predict reli- ably the effect of an external perturbation on the electronic and vibrational properties of the investigated medium (either ordered or disordered). Raman spectroscopy can then be used to identify the constituting species, study the compositional uniformity, crystallinity, doping level, and to probe locally the temperature and stress. At the industrial level, in modern clean room facilities micro-Raman spectroscopy (ixRS) has become (like many other optical techniques) a very attractive characterization tool. This is because of its contactless and nondestructive nature. Thanks to recent turnkey Raman systems, one can perform repetitively large area mapping with spatial resolution down to 300 nm. The use of several laser wavelengths enables then to probe the in-depth profile of a given semiconductor or device. All these features confirm the unique versatility and potentialities of |xRS imaging in microelectronics. In this chapter, we illustrate how this unique characterization tool covers the whole process flow of fabrication of modern electronic and optoelectronic devices. The first section will give some background considerations on Raman imaging in semiconductor physics. The second section will be devoted to the study of advanced wafers manufacturing and epitaxial layers development, such as graphene, Si _(1-x)Ge_x alloys, and strained Si wafers. The third section will focus on the most popular application of Raman imaging in microelectronics: stress monitoring. Finally the fourth one will address how Raman imaging can contribute to the final device inspection.