Application Advantages of Schottky Diodes in Circuits — SUNMATE

Schottky diode is a semiconductor component made of metal materials as the positive stage and N-type semiconductor as the negative stage, which uses the potential barrier generated on the surface of both to have the characteristics of rectifier. It is a hot carrier diode. Schottky diode is mainly used as rectifier diode, freewheeling diode, maintenance diode, etc. in the power circuit, and it is mainly used in the power circuit with low voltage and large current flow, such as power transformer, soft starter Inverter power supply, fiber optic communication. It is widely used in small signal circuits of semiconductor radios, radio recorders, televisions, communications and other equipment. Today, let's take a look at the application advantages of Schottky diodes in circuits:

Schottky diode

Schottky diode is a metal material semiconductor component made of precious metals such as gold, silver, aluminum and platinum as the positive stage, and N-type semiconductor B as the negative stage. It uses the potential barrier generated on the surface of both to have the characteristics of a rectifier. Since there are many electronic devices in the N-type semiconductor, and there is only a small amount of free charge in the precious metal, the electronic devices will diffuse from the high concentration B to the low concentration A.

If there is no cavitation in metal material A, there will be no outward diffusion of cavitation from A to B. As electronic devices continue to diffuse from B to A, the concentration value of B's surface electronic devices gradually decreases, and the surface charge balance is destroyed, resulting in the formation of a potential barrier with an electric field direction of B → A. However, within the effectiveness of this electrostatic field, the electronic devices in A can also cause a drifting exercise from A to B, thereby weakening the electrostatic field generated by external diffusion exercise. When a certain total width of the space charge region is created, the drift and fitness movement of electronic devices caused by the electrostatic field and the diffusion and fitness movement of electronic devices caused by different concentration values achieve a relative balance, resulting in the Schottky barrier.

The typical internal power circuit structure of Schottky rectifier tube is to use N-type semiconductor as the substrate, on which an N-neneneba epitaxial layer with arsenic as the dopant is generated. Anodizing should use raw materials such as molybdenum or aluminum to make a barrier layer. Use silicon dioxide (SiO2) to remove the electrostatic field in the edge area and improve the compressive value of water pipes.

The N-type substrate has a small on state resistor, and its inclusion concentration is 100% times higher than that of the H-layer. An N+negative electrode layer is generated below the substrate, which reduces the circuit resistance of the negative electrode. According to the main parameters of the optimized structure, a Schottky barrier is generated between the N-type substrate and the anodized metal material, as shown in the following figure. When a forward bias voltage is applied on both sides of the Schottky barrier (positive for anodized metal material insertion and negative for N-type substrate insertion), the Schottky barrier layer decreases and its internal resistance decreases; On the contrary, if a reverse bias is applied on both sides of the Schottky barrier, the Schottky barrier layer becomes larger and its internal resistance increases.