Microelectronics surface characterization

Static SIMS. The static SIMS instrument was briefly described in the instrumental section. Static SIMS has been applied to the study of metal surfaces (fig.) oxide formation (11), and catalysts (ii fi6) but static SIMS is not widely used in microelectronics materials characterization. A major limitation of static SIMS for microelectronics applications is the inability to obtain a detectable signal from a very small area on the sample. The low energy low current density primary ion source used in static SIMS produces a lower count rate per unit area of sample than does the higher energy higher current density used in dynamic SIMS. 

High technology surfaces (e.g., microelectronics) are often intentionally patterned, and light scattering may be used for subsequent characterization of the pattern. In... 

The most frequently applied analytical methods used for characterizing bulk and layered systems (wafers and layers for microelectronics see the example in the schematic on the right-hand side) are summarized in Figure 9.4. Besides mass spectrometric techniques there are a multitude of alternative powerful analytical techniques for characterizing such multi-layered systems. The analytical methods used for determining trace and ultratrace elements in, for example, high purity materials for microelectronic applications include AAS (atomic absorption spectrometry), XRF (X-ray fluorescence analysis), ICP-OES (optical emission spectroscopy with inductively coupled plasma), NAA (neutron activation analysis) and others. For the characterization of layered systems or for the determination of surface contamination, XPS (X-ray photon electron spectroscopy), SEM-EDX (secondary electron microscopy combined with energy disperse X-ray analysis) and... 

Adhesion of polyimides to inorganic substrates is of great importance to the microelectronics industry [1, 2]. The polyimide films are deposited most often by spin coating the polyamic acid (PAA) usually from a TV-methylpyrrolidone (NMP) solution onto the substrate surface followed by thermal imidization at temperatures up to 400<>C. The most studied polyimide is the pyromellitic dianhydride-oxydianiline (PMDA-ODA), which exhibits excellent mechanical and dielectric properties, but not so good adhesion characteristics. The latter has been generally overcome by application of an adhesion promoter, such as y-aminopropyltriethoxysilane [3-7]. The reactions of APS (coated from water solution) with the silicon dioxide surface as well as with polyamic acid have been well characterized by Linde and Gleason [4] however, we do not have such detailed information available on APS interaction with other ceramic surfaces. 

Oxides surfaces are finding continuous new applications in advanced technologies like in corrosion protection, coating for thermal applications, in catalysis as inert supports or directly as catalysts, in microelectronics for their dielectric properties films of magnetic oxides are integral components in magnetic recording devices and many microporous materials are based on oxides. For all these reasons there is a considerable effort to better characterize the surface and the interface of oxide materials [1,2]. 

In this review the various modes of SIMS and examples of their applications are discussed. SIMS depth profiles are widely used to study dopant profiles and Intermetallic diffusion. The extreme surface sensitivity and low concentration detection limits of SIMS make It useful for Investigation of substrate and metallization cleaning processes. SIMS elemental Imaging Is also used In contamination studies. The ability of SIMS to provide Isotopic Information has allowed elegant mechanistic studies. The Identification and determination of the relative abundance of various molecular or elemental species by SIMS Is applicable to the development characterization and understanding of microelectronic processing. The capability of SIMS In the area of quantitative analyses Is also discussed. 

The chemical spatial resolution of state-of-the-art scanning AES systems coupled with the surface sensitivity of the technique make them uniquely capable for characterization of modern microelectronic devices. This will mean greater dependence on AES for both failure analysis and process development. The demands of greater production... 

The development of new methods for studying surfaces is progressing rapidly, precipitated by the phenomenal growth and interest in surface physics and chemistry which was stimulated, in part, by the need for clean, well-characterized surfaces for microelectronic and other high-technology applications. The biomaterials field should be able to capitalize upon this plethora of new methods which have appeared primarily in the past 15 years. In particular, many of the new techniques measure surface chemistry directly, in contrast to older methods which often required indirect or thermodynamic data. At the present stage of development in the field of surface analysis, a picture of a surface must be built up by using a variety of methods. Combinations of the classic surface analysis methods (e.g., con-... 

---