4.2 Capacitance Estimation :

Consider the simple rectangular wire placed above the semiconductor substrate as shown in Fig 4.1. The capacitance between the parallel plates is proportional to its proportional to its cross section A (length L multiplied by width W) and inversely proportional to the separation t between the plates. The capacitance can be expressed as

                                                                                    

Where is the permittivity of free space, k is the relative dielectric constant of the insulator and t is the thickness of the insulating material.