Classification of Crystal Diodes 3

4. A diffusion diode heats a single crystal of N-type germanium or silicon in a high-temperature P-type impurity gas, causing a portion of the surface of the single crystal to become P-type, thus forming a PN junction. Due to the small forward voltage drop of PN junction, it is suitable for high current rectification. Recently, the mainstream use of high current rectifiers has shifted from silicon alloy type to silicon diffusion type.

5. The production method of the PN junction of the table type diode is the same as that of the diffusion type, but only the PN junction and its necessary parts are retained, and the unnecessary parts are corroded away with medicine. The remaining part takes on a rectangular shape, hence the name. The initial production of the tabletop was made using diffusion method on semiconductor materials. Therefore, this type of tabletop is also called a diffusion tabletop. For this type, it seems that there are few product models used for high current rectification, while there are many product models used for low current switches.

6. A planar diode is formed on a semiconductor single crystal wafer (mainly an N-type silicon single crystal wafer) by diffusing P-type impurities and utilizing the shielding effect of the silicon wafer surface oxide film to selectively diffuse only a portion of the PN junction on the N-type silicon single crystal wafer. Therefore, there is no need to adjust the PN junction area for drug corrosion. Due to the flatness of the semiconductor surface, it is named. Moreover, the surface of PN bonding is recognized as a type with good stability and long lifespan due to being covered by an oxide film. Initially, the semiconductor materials used were formed using epitaxial methods, hence the planar type was also referred to as epitaxial planar type. For planar diodes, there seem to be few models used for high current rectification, while there are many models used for low current switching.diode