In the field of semiconductor manufacturing, materials often need to be manipulated in various ways to take full advantage of their electrical or physical properties. One of the methods of accomplishing this is doping a material, which involves forcibly inserting different elements into a material to change its physical or electrical properties. An example of this would be doping pure silicon with an element that has fewer electrons than silicon like boron or an element that has more electrons than silicon like phosphorus. This will results in a doped sample of silicon that is either deficient in or abundant with electrons, which has some useful electrical applications. The method of doping that is used at RIT is called ion implantation, which involves accelerating dopant ions through an electric field and focusing them into a beam that is directed at a silicon substrate. One of the issues that arises from this method of doping is that when ions bombard a silicon crystal, the lattice structure of the crystal is damaged down to a certain depth. This damage can be repaired by heating the silicon crystal, which will cause the crystal lattice to repair itself based on the lattice pattern of the undamaged portion of the silicon crystal. This is known as annealing the silicon, and is usually done immediately after an ion implant.
This ion implant process does have some potential to be improved. Instead of leaving the implant and annealing steps as separate processes, they could potentially be combined. Silicon samples that are being implanted usually rest on some kind of chuck. By heating this chuck, any damage that occurs in the silicon crystal structure can be repaired during the implant process. This could cut down on manufacturing time by combining two steps, and could even improve the doping process through the added heat aiding in the diffusion of dopants.
-Austin Whitaker
Technical Writing and Editing 