gate

Synopsys: gate(“gategeometry”,coordinates)

gate is a class of NanoTCAD ViDES devoted to define the points of the grid in which Dirichlet boundary conditions have to be imposed. Points belonging to the gate has their electrostatic potential fixed to a predetermined value imposed by the user.

The attribute of the gate class are the following:

• geometry : (string) describe the geometry of the gate. The implemented geometries are:
• “hex”: hexahedron geometry. If “gategeometry” is equal to “hex”, 6 values have to be passed to the gate class, and in particular, xmin, xmax,ymin,ymax,zmin,zmax, which univocally define the limits of the hexahedron geometry. For example: top_gate=gate(“hex”,-1,1,-2,3,5,10); In this way, the attributes xmin, xmax, ymin, ymax, zmin, zmax, are set to -1,1,-2,3,5,10, respectively.
• “trapz”: trapezoidal gate geometry in the y-z plane (ONLY WORKS WITH 3D GRID). If  “gategeometry” is equal to “trapz”, 10 values have to be passed to the gate class, and in particular, the xmin and xmax, as well as the y and z coordinates of the points which define the generic trapezoidal gate. The points have to be ordered in the following way. P1 is the point with the minimum y coordinate. The other points are ordered along the perimeter in the anti-clockwise direction. An example is shown in the figure below. In particular if xmin is equal to 1 and ymin to 2, then the trapezoidal gate is defined as:trap_gate=gate(“trapz”,1,2,10,150,160,10,170,240,20,270);
• Ef : (double) Fermi level of the gate. Please note that the Fermi level is the opposite of the electrostatic potential.
• index: (array of double) this attribute is created by the interface3D class, and it specify the indexes along the 3D domain of the points belonging to the gate.