There are many different ways to make MOSFETs on the semiconductor. The simplest method is shown in the diagram to the right of this text. The blue part represents P-type silicon, while the red part represents N-type silicon. The intersection of the two types makes a diode. In silicon semiconductor, there is a quirk called the "Depletion Region". In doped silicon, with one part being doped N-Type, and one part being doped P-Type, a depletion region will naturally form on the intersection between the two. This is because of their acceptors and donors. P-type silicon has acceptors, also known as holes, which attract electrons towards them. The N-Type silicon has donors, or electrons, which are attracted to holes. In the border between the two, the electrons from the N-Type fill the holes in the P-type. This results in the acceptor, or P-type atoms becoming negatively charged, and since negative charges attract positive charges, acceptors, or holes, will flow towards the "junction". On the N-Type side, there is a positive charge, which results in the donors, or electrons, flowing towards the "junction." When they get there, they will be repelled by the negative charge on the other side of the junction, since alike charges repel. The same will happen on the P-Type side, the donors, or holes will be repelled by the positive area in the N type side. No electricity can flow between the two, since no electrons can move to the other side. 