|dc.description.abstract||Gallium nitride (GaN) materials are attractive to be used in high power amplifier and RF power applications for 5G communication technology due to their high breakdown electric field, high electron mobility and high electron saturation speed. However, GaN power devices operating at high currents and high voltages will cause high channel temperature and cause reliability issues. The self-heating effect causes the drain current to drop and limits the output power, which also affects the lifetime of the devices. One of the effective ways to reduce thermal effects is the backside via process and layout. In this paper, two AlGaN/GaN high electron mobility transistors (HEMTs) with different backside vias are used to study thermal and high frequency characteristics. Connecting the source through the backside via to the backside of the wafer can effectively dissipate heat. A transistor with a backside via outside the active region is called an OSV (outside backside via) layout transistor; in addition to having a backside via outside the active region, there is an additional backside via in the middle source of active region. The device is called an ISV (internal backside via) layout transistor. The DC characteristics of the two transistors are presented at different temperatures, including thermal resistance analysis, and a small signal model was established to study the dependence of the intrinsic parameters of the two transistors on temperatures.
In addition, the 5G communication technology has a very high linearity requirement. This paper discusses the variation and influence of the linearity of different gate-to-source length (LGS) transistors. In general, the resistance is a linear component, and the larger the resistance, the greater the linearity of the transistor. In order to improve the linearity of GaN devices, AlGaN/GaN HMETs with different gate-to-source distance (LGS) layouts are designed to study DC characteristics, high frequency characteristics, large signal characteristics and linearity.