Deposition time, silicon nitride

In the present chapter, we will turn our attention to films deposited by thermal CVD that are either dielectrics or semiconductors. There are, as one would expect, many films that can be deposited by this technique. In addition, there are many gaseous reactants that one can use to create each film, the choice depending on the film characteristics desired. Rather then attempt to catalogue all of the possible films and reactants, we will choose instead to focus on silicon dioxide, silicon nitride, polysilicon, and epitaxial silicon as the films of interest. At the same time, we will only look at those reactant gases that have been used for integrated circuit manufacture. An excellent survey of the film types that can be deposited by CVD and the many reactants that have been used to obtain them has been given by Kern.1... 

After the quality of the plasma silicon nitride films and their dependence on the several system parameters has been evaluated, there still remains the question of whether or not a given process can be commercially viable. Here the issue is the deposition rate and the uniformity of deposition on a wafer and over all wafers in the reactor. The ideal solution is to deposit at a high rate uniformly over many wafers at one time. We cannot simply stack many wafers close together and run a low-pressure process, as in thermal LPCVD, because we have to be sure the plasma discharge is uniform as well. 

In order to improve the sensor response time, a thin hydrogel layer was directly deposited onto the backside of the bending plate covered with a 220 nm thick PECVD silicon nitride film and with a 17 run thick adhesion promoter layer (Fig. 2c). The final thickness of the dried and then cross-linked hydrogel layer was 4... 50 pm. 

Figure 27 Raman spectra of the carbon deposited on the wear scar of the silicon nitride plate in the experiment referred to in the text (a) 180 sec run time (b) 240 sec run time [60]. (Reproduced from Lubrication Engineering, 49, Vlcek, B. L., et aL, Lubrication of ceramic contacts by surface-deposited pyrolytic carbon, pp. 463-471. Copyright 1993, with permission from Society of Tribol-ogists and Lubrication Engineers.)...

Copper is intrinsically a better metal than aluminum for the metallization of IC s. Latest developments in MOCVD show that it can be readily deposited without major changes in existing processing equipment. Diffusion problems are minimized and it appears that present barrier materials, such as titanium nitride or titanium-tungsten alloys, should provide adequate diffusion barriers for the copper-silicon couple, certainly up to the highest temperatures presently used in IC s processing (see Ch. 6). The development of CVD copper for semiconductor metallization is on a considerable scale at this time.Clt ]... 

Up to now, most work on cBN deposition has been done using single crystal silicon substrates. Those films grow in a typical phase sequence which has been shown for the first time by Kester et al. [37] in 1993 and since then confirmed by many groups At first an amorphous layer at the interface to the substrate is formed which is usually referred to as aBN. This layer probably contains also some silicon from the substrate and is due to ion-induced intermixing. After that a turbostratic boron nitride (tBN) layer is formed. Turbostratic boron nitride is a BN form consisting of nearly parallel hBN-like layers which, however, do not have defined three-dimensional orientation. The distance of these layers is a few percent enlarged in comparison to the hBN crystal (see e.g. [1]). Under deposition conditions which... 

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