Insulate-Gate Bipolar Transistor—IGBT(绝缘栅双极晶体管)

Insulate-Gate Bipolar Transistor—IGBT

绝缘栅双极晶体管（Insulate-Gate Bipolar Transistor—IGBT）综合了电力晶体管（Giant Transistor—GTR）和电力场效应晶体管（Power MOSFET）的优点，具有良好的特性，应用领域很广泛；IGBT也是三端器件：栅极，集电极和发射极。 IGBT(Insulated Gate Bipolar Transistor)是MOS结构双极器件，属于具有功率MOSFET的高速性能与双极的低电阻性能的功率器件。IGBT的应用范围一般都在耐压600V以上、电流10A以上、频率为1kHz以上的区域。多使用在工业用电机、民用小容量电机、变换器（逆变器）、照相机的频闪观测器、感应加热（InductionHeating）电饭锅等领域。根据封装的不同，IGBT大致分为两种类型，一种是模压树脂密封的三端单体封装型，从TO－3P到小型表面贴装都已形成系列。另一种是把IGBT与FWD （FleeWheelDiode）成对地（2或6组）封装起来的模块型，主要应用在工业上。模块的类型根据用途的不同，分为多种形状及封装方式，都已形成系列化。

The Insulated-Gate Bipolar Transistor (IGBT) combines the advantages of the Giant Transistor (GTR) and the Power MOSFET, and has good characteristics with a wide range of applications. The IGBT is also a three-terminal device: gate, collector, and emitter. The IGBT is a MOS structure bipolar device, which is a power device that has the high-speed performance of a power MOSFET and the low resistance performance of a bipolar. The application range of IGBTs is generally in areas with a voltage resistance above 600V, a current above 10A, and a frequency above 1kHz. It is widely used in industrial motors, small capacity civilian motors, converters (inverters), camera strobe observers, induction heating (Induction Heating) rice cookers and other fields. According to the different packaging, IGBTs are roughly divided into two types. One is a three-terminal monolithic package sealed with molded resin, from TO-3P to small surface mounting have formed a series. The other is a module type that packages IGBTs and FWDs (FleeWheelDiodes) in pairs (2 or 6 groups), mainly used in industry. The types of modules are divided into various shapes and packaging methods according to different uses, and have formed a series.

IGBT是强电流、高压应用和快速终端设备用垂直功率MOSFET的自然进化。MOSFET由于实现一个较高的击穿电压BVDSS需要一个源漏通道，而这个通道却具有很高的电阻率，因而造成功率MOSFET具有RDS(on)数值高的特征，IGBT消除了现有功率MOSFET的这些主要缺点。虽然最新一代功率MOSFET器件大幅度改进了RDS(on)特性，但是在高电平时，功率导通损耗仍然要比IGBT 高出很多。IGBT较低的压降，转换成一个低VCE(sat)的能力，以及IGBT的结构，与同一个标准双极器件相比，可支持更高电流密度，并简化 IGBT驱动器的原理图。

The IGBT is the natural evolution of the vertical power MOSFET for high current, high voltage applications and fast terminal devices. The MOSFET needs a source-drain channel to achieve a higher breakdown voltage BVDSS, but this channel has a high resistivity, which results in the power MOSFET having a high RDS(on) value. The IGBT eliminates these main disadvantages of the existing power MOSFET. Although the latest generation of power MOSFET devices has greatly improved the RDS(on) characteristics, at high levels, the power conduction loss is still much higher than that of IGBT. The lower voltage drop of IGBT is converted into a low VCE(sat) capability, and the structure of IGBT can support a higher current density compared to the same standard bipolar device, and simplify the schematic of the IGBT driver.

图1（a）所示为一个N 沟道增强型绝缘栅双极晶体管结构， N+ 区称为源区，附于其上的电极称为源极。N+ 区称为漏区。器件的控制区为栅区，附于其上的电极称为栅极。沟道在紧靠栅区边界形成。在漏、源之间的P 型区（包括P+ 和P 一区）（沟道在该区域形成），称为亚沟道区（ Subchannel region ）。而在漏区另一侧的P+ 区称为漏注入区（ Drain injector ），它是IGBT 特有的功能区，与漏区和亚沟道区一起形成PNP 双极晶体管，起发射极的作用，向漏极注入空穴，进行导电调制，以降低器件的通态电压。附于漏注入区上的电极称为漏极。

Figure 1(a) shows a structure of an N-channel enhancement type Insulated Gate Bipolar Transistor (IGBT). The N+ region is called the source region, and the electrode attached to it is called the source electrode. The N+ region is called the drain region. The control region of the device is the gate region, and the electrode attached to it is called the gate electrode. The channel is formed close to the boundary of the gate region. The P-type region (including P+ and P regions) between the drain and source (where the channel is formed) is called the sub-channel region. The P+ region on the other side of the drain region is called the drain injection region, which is a unique functional area of IGBT. It forms a PNP bipolar transistor together with the drain region and sub-channel region, acts as an emitter, injects holes into the drain electrode, conducts modulation, and reduces the on-state voltage of the device. The electrode attached to the drain injection region is called the drain electrode.

Figure 1(a) 

IGBT 的开关作用是通过加正向栅极电压形成沟道，给PNP 晶体管提供基极电流，使IGBT 导通。反之，加反向门极电压消除沟道，流过反向基极电流，使IGBT 关断。IGBT 的驱动方法和MOSFET 基本相同，只需控制输入极N一沟道MOSFET ，所以具有高输入阻抗特性。当MOSFET 的沟道形成后，从P+ 基极注入到N 一层的空穴（少子），对N 一层进行电导调制，减小N 一层的电阻，使IGBT 在高电压时，也具有低的通态电压。

The switching action of the IGBT is to form a channel by adding a positive gate voltage, providing a base current for the PNP transistor, and making the IGBT conduct. Conversely, adding a reverse gate voltage eliminates the channel and flows through the reverse base current, turning off the IGBT. The driving method of IGBT is basically the same as that of MOSFET. It only needs to control the input pole N-channel MOSFET, so it has high input impedance characteristics. After the channel of MOSFET is formed, holes (minorities) are injected from the P+ base to the N-layer, and the N-layer is modulated for conduction, reducing the resistance of the N-layer, so that IGBT also has a low on-state voltage at high voltage.