The effect of electrostatic voltage accumulation on components
Core Tip: Voltage breakdown refers to the breakdown of a semiconductor PN junction or dielectric layer under overvoltage. In modern VLSI circuits, the thickness of the gate oxide layer is as thin as nanometers, and electrostatic voltages as small as one hundred volts or tens of volts are sufficient to cause component failure or performance degradation. The main source of overvoltage is triboelectric. When a person walks into the room or
Voltage breakdown refers to the breakdown of a semiconductor PN junction or dielectric layer under overvoltage. In modern VLSI circuits, the thickness of the gate oxide layer is as thin as nanometers, and electrostatic voltages as small as one hundred volts or tens of volts are sufficient to cause component failure or performance degradation.
The main source of overvoltage is triboelectric. When a person walks into a room or simply removes an integrated circuit from a plastic envelope material, it can generate a voltage of 15,000 - 20000V, far exceeding the electrostatic breakdown voltage. Taking a MOS field effect transistor as an example, a metal aluminum gate, an insulating dielectric layer SIO2, and a semiconductor N-channel, such a structure is equivalent to a flat-plate capacitor having a capacitance of about 3 PF.
When static charge accumulates on the aluminum grid, it is known from V = Q / C that even a small amount of charge causes the voltage to rise very high. The withstand voltage of the insulating dielectric layer SIO2 is only about 100V. When the electrostatic voltage reaches or exceeds the withstand voltage value, the oxide film will be broken down, causing pinholes to make the gates communicate, damaging the device, causing hidden dangers, or making the device Invalid.
Power breakdown refers to breakdown of a semiconductor PN junction, an insulating dielectric layer, a connecting wire, etc. under an overcurrent, which is related to the shape, duration, and energy accumulation of the electrostatic discharge pulse. An electrostatic discharge current flows through the interior of the integrated circuit causing an increase in the temperature of the PN junction.
Some may burn the internal connecting wires or cause the internal connecting wires to narrow, and some may cause alloying or metal diffusion, which may eventually cause permanent damage or severe aging of the device. Electrical aging is the "soft breakdown" of the most headaches. It can't be found at the time, but it may fail at any time. At this time, the electronic equipment that uses it will undoubtedly bring great hidden dangers.