Therefore, this compensating design is not suitable for achieving sharp corners in any kind of etchant.
The shape and size of the compensating design strongly depends on the type of etchant, etching depth and the orientation of wafer surface.
Figure 24 Sequentially etched shape for a mesa structure with triangular shape compensating design in surfactant added 25 wt% TMAH [120].
(i) Triangle: The triangular shape geometry, as shown in Figure 22, is a simplest compensating design in terms of determining its shape and dimensions [90,91,120].
As discussed earlier, surfactant-added THAH is not feasible for the fabrication of convex corners because the planes appearing at the edges of the compensating design have lower etch rates than {100}.
In the case of {100} wafer, <100> oriented compensating design provides sharp edge corner under certain conditions, but its high spatial requirement is a main drawback, especially when the bent grooves are required to be realized.
In different concentration of TMAH, 25% TMAH is the most favorable choice for minimizing the undercutting while achieving smooth surface finish with reasonable etch rate of {100} planes [134-136,140-142,145,146]. In this etchant, any shape of the compensating design can conveniently be fitted in the accessible space for the formation of grooves for chip isolation and bent V-grooves.
Both kinematic and dynamic uncertainties are estimated and compensated by designed reduced-order linear extended state observes (LESOs).
The mismatch between the hypothetical hardware model and real hardware design should be compensated for in designing an efficient algorithm.
"The aggressive behavior of New York pedestrians may be a way of compensating for design that doesn't reflect what's going on in terms of use," Mr. Greenberg said.
In this paper, various kinds of compensating designs published so far are discussed.
