氮化鎵(GaN)材料由於其高崩潰電場、高電子遷移率和高電子飽和速度，是5G行動通訊技術之高功率放大器和RF功率元件的熱門應用材料。然而，在高電流和高電壓下操作的GaN功率元件將導致通道高溫並引發可靠度問題。自我發熱(self-heating)效應會導致汲極電流下降並限制輸出功率，這也會影響元件的使用壽命，為了在高功率性能下操作元件，必須在元件製作和電路應用之前考慮散熱問題。減少熱效應的有效方法之一是背向穿孔(backside via)製程和佈局。在本文中，使用了兩種具有不同背向穿孔佈局的AlGaN/GaN高電子遷移率電晶體(HEMT)以研究熱特性與高頻特性。將源極透過背向穿孔連接至晶片的背面可以有效地散熱。在整個主動區外具有背向穿孔的電晶體稱為OSV (outside backside via)佈局電晶體；除了在主動區外具有背向穿孔之外，在主動區源極中有一個額外背向穿孔的電晶體稱為ISV (internal backside via)佈局電晶體。在不同溫度下分析兩種電晶體之直流特性，包括熱阻分析等；並且建立小訊號模型，研究兩種電晶體之本質參數對於溫度的相依性程度。 此外，5G行動通訊技術對於線性度的要求非常高，本文探討不同閘極對源極長度(LGS)之電晶體其線性度之變化及影響。一般而言，電阻是一個線性的元件，電阻越大的電晶體會有較大的線性度。為了改善氮化鎵元件之線性度，設計不同閘極至源極距離(LGS)佈局之AlGaN/GaN HMETs，研究其直流特性、高頻特性、大訊號特性和元件線性度。 ;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.
