Micro LED

solidex07.in : Micro LED

Requires: Victory Mesh/Atlas
Minimum Versions: Victory Mesh 1.4.7.R / Atlas 5.28.0.R
A typical micro LED structure contains many tightly spaced layers of material. These devices are relatively simple to generate within standard etch/deposit process engines. However, the cap stage is more complex. In many designs the capping stage results in a region of material that is difficult to shape using a typical etch/deposit engine.
In this example a method showing how Victory Mesh can generate a micro LED entirely using solid modeling commands is demonstrated. This LED will also contain a realistic cap stage.
The solid modeling of the LED will create all layers in a single step, and then slice the centre of the LED into place. This slice is repeated with two cylinders of varying size. The slice command inserts interfaces into the mesh that match the boundary of the slice shape (in this case a cylinder). The material and tag statements can then be used to change the separate regions created. In this case their materials are changed.
The LED is now in a similar state as would be created using etch/deposit, but note that there is no gas on top. Since this is not an etch/deposit engine, there is no need to create gas. Instead there is a boundary interface at the top of the structure, where an ellipsoid cap can be attached using the join command.
It is possible to take a cutplane to examine the internal structure of the device. The device is also suitable for a Delaunay remesh, and refinement around the InGan interface can be added as normal. In order to run a device simulation on this structure there will need to be electrodes and doping present. Victory Mesh contains commands to add these to the device. In this case volume electrodes are attached to create the anode and cathode (other electrode types are available), and constant doping to the GaN regions.
Using the quantum well model as well as the optical recombination model with spontaneous emission, it is possible to obtain the LED emission spectrum at various bias conditions.