Research On ESD Protection Device Based On 0.35?m SiGe Process

In recent years,the SiGe heterojunction process has been widely used in the wireless field because it can provide a solution for high-frequency devices and is compatible with common silicon processes.The reliability issues under SiGe process has also gradually gained attention.Electrostatic discharge(ESD)phenomenon is an important factor affecting device reliability,but ESD protection research under SiGe process still needs more research results.Based on the 0.35 um SiGe process,the ESD protection devices under SiGe process are studied in this thesis.The main contents are as follows:This article first introduces the basic concepts of ESD protection design.The first thing to do in ESD design is to summarize the actual ESD events and get a physical model that has guiding significance in the actual design.Firstly,human body model(HBM),machine model(MM),and component charging model(CDM)are introduced which correspond to different physical test models with different pulse test waveforms.A model specifically for testing,the TLP model,is introduced to study the device characteristics.The concept of the design window for ESD design is introduced,which involved two basic requirements for ESD protection: preventing IC damage and not affecting the normal operation of the IC.Finally,the failure mechanism and judgment method of ESD are introduced.After the introduction of the basic concepts of ESD protection,some conventional devices based on the SiGe process are introduced,including four basic devices: diode,HBT,MOSFET,and SCR.Some variations of diodes under this process is also introduced.For HBT devices,changes in the characteristics of the device at different temperatures are also discussed.The performance data of these conventional devices has great guiding value for designing new device.Finally,this paper introduces four new devices under the SiGe process.Firstly,external HBT-triggered SCR structures and embedded HBT-triggered SCR structures are introduced witch can reduce the trigger voltage of SCR devices.Then,the SCR integrated with HBT structure,and the bidirectional SCR integrated with HBT structure are introduced witch can reduce the area of SCR devices.These device structures,implementation methods,and experimental data provide many new references for ESD design.The test results show that,except for some devices which are specifically mentioned,the remaining devices have the protection capacibility of more than 4kV and can meet most ESD protection requirements.