Tetra-ethyl-ortho-silicate

Sharma et al. [40] have used tetra-ethyl-ortho-silicate (TEOS) for the formation of Si02 matrix. The chemical structure of TEOS can be represented as shown in... 

Fig. 4 (a) Chemical structure of tetra-ethyl-ortho-silicate (TEOS). (b) Removal of two oxygen atoms from TEOS. (c) Mechanism depicting how TEOS chemisorbs onto silanol groups (Si-OH) on surface, (d) Formation of Si-O-Si bridges by elimination reactions with neighboring molecules. (Figure adapted from [40])... 

Also shown in Fig. 2 are the measured spectrum of a TEOS (tetra-ethyl-ortho-silicate)-TiN-Al stack, overlaid with the theoretical spectrum. The theoretical spectrum was based on such substrate modeling treatment. Given this empirical spectrum, both the TiN and TEOS thicknesses can be simulated and determined simultaneously. Alternatively, the TiN thickness can be fixed with only the TEOS needing to be measured. The latter method is better than the former because the more unknown film thicknesses there are, the more error is introduced. This can be demonstrated by the data in Table I, where the measurement results of the oxide thicknesses on TiN-Al substrates on the same wafer, for TiN thickness fixed and varying, are compared. 

In literature, numerous precursors for CVI of silica are proposed. Most common are silane [6,7,10], Tetra Ethyl Ortho Silicate (TEOS) [8,9,11,12] and silicon tetrachloride [13,14], As oxygen source mainly pure oxygen or water vapour in a helium or nitrogen flow is used. In... 

However, others suggest the opposite conclusions (Tamboli et al., 2004 Lei and Luo, 2004). Tamboli et al. suggested that the MRR is increased with an increase in abrasive size in CMP for tantalum and tetra-ethyl ortho-silicate (Tamboli et al., 2004). As shown in Figure 11.10(b), Lei et al. also showed that larger abrasive size leads to an increase in MRR for polishing hard disk substrate... 

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