Plasma isotropic

Figure C2.13.5. Schematic illustrations of isotropic etching by a neutral gas and anisotropic plasma etching.

The dynamic profile of carnosine was investigated by comparing MD simulations in isotropic solvents (i.e. water and chloroform) with simulation of the compound bound to serum carnosinase (CNl) [22]. This enzyme is characterized by its distribution in plasma and brain, and its ability to hydrolyze also anserine and homocarnosine [23]. The conformational profile of carnosine can be defined by... 

Isotropic Profile No Overetch Liquid or Plasma Etching... 

Figure 1. Cross sections of films etched with liquid or plasma etchants. The isotropic profile represents no overetch, and can be generated with liquid or plasma etch techniques. The anisotropic profile requires plasma...

Three different dry etch techniques were investigated isotropic O2 plasma etching in a Tegal 200 reactor, R.I.E. in a parallel-plate in-house modified Tegal AOO reactor and R.I.M. in a Veeco, Model RG-830. The conditions of operation for each system were as follows where time is the time to etch 1.2 p of fully cured polyimide. 

Figure 2. SEM of a 5 y, 5 fim via in 1.5 /j. P12545. Isotropic Os plasma etch conditions were used.

Finally, the most important problem is whether one can draw any conclusions for the general three-dimensional problem. Can one, for example, in the absence of helicity transfer directly to the case of isotropic three-dimensional general turbulence the concepts of diamagnetism of a turbulent plasma and of temporary growth of fields with a simultaneous decrease of the scale. These concepts can be applied not only to an infinite medium, but also to situations with boundary conditions at finite distances. But this problem is only posed here—its solution is a matter for the future. 

Heavily doped (>1018/cm3) n-type Si and poly-Si etch faster in Cl- and F-containing plasmas than do their boron-doped or undoped counterparts (103a, 105, 111, 112). Because ion bombardment is apparently not required in these cases, isotropic etch profiles (undercutting) in n + poly-Si etching often occur. Although the exact mechanisms behind these observations are not completely understood, enhanced chemisorption (103b, 111) and space charge effects on reactant diffusion (112) have been proposed. 

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