Title :
Performance Enhancement of Flip-Chip Packaged AlGaN/GaN HEMTs Using Active-Region Bumps-Induced Piezoelectric Effect
Author :
Szu-Ping Tsai ; Heng-Tung Hsu ; Che-Yang Chiang ; Yung-Yi Tu ; Chia-Hua Chang ; Ting-En Hsieh ; Huan-Chung Wang ; Shih-Chien Liu ; Chang, Edward Yi
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
We experimentally investigated the impact of different bump patterns on the output electrical characteristics of flip-chip (FC) bonded AlGaN/GaN high-electron mobility transistors in this letter. The bump patterns were designed and intended to provide different levels of tensile stress due to the mismatch in the coefficient of thermal expansion between the materials. After FC packaging, a maximum increase of 4.3% in saturation current was achieved compared with the bare die when proper arrangement of the bumps in active region was designed. In other words, a 17% improvement has been observed on the optimized bump pattern over the conventional bump pattern. To the best of our knowledge, this is the first letter that investigates the piezoelectric effect induced by FC bumps leading to the enhancement in device characteristics after packaging.
Keywords :
aluminium compounds; flip-chip devices; gallium compounds; high electron mobility transistors; piezoelectricity; stress effects; thermal expansion; AlGaN-GaN; FC bond; active region; active-region bumps-induced piezoelectric effect; bare die; bump pattern impact; flip-chip packaged HEMT; high-electron mobility transistor; output electrical characteristic; performance enhancement; saturation current; tensile stress; thermal expansion coefficient; Aluminum gallium nitride; Gallium nitride; HEMTs; MODFETs; Packaging; Strain; Tensile stress; AlGaN/GaN; coefficient of thermal expansion (CTE); flip-chip (FC); high-electron mobility transistors (HEMTs); tensile strain; tensile strain.;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2014.2324619
