Title :
Backside copper metallization of GaAs MESFETs using TaN as the diffusion barrier
Author :
Chen, Chang-You ; Chang, Li ; Li Chang ; Chen, Szu-Hung
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
6/1/2001 12:00:00 AM
Abstract :
Backside copper metallization of GaAs MESFETs using TaN as the diffusion barrier was studied. A thin TaN layer of 40 nm was sputtered on the GaAs substrate before copper film metallization, as judged from the data of X-ray diffraction (XRD), Auger electron spectroscopy (AES), and cross-sectional transmission electron microscopy (TEM), the Cu/TaN films with GaAs were very stable without interfacial interaction up to 550°C annealing; the copper metallized MESFETs were thermally stressed at 300°C. The devices showed very little change in the device characteristics (<3%) after thermal stress, and the changes of the electrical parameters and RF characteristics of the devices after thermal stress were of the same order as those devices without Cu metallization, these results show that TaN is a good diffusion barrier for Cu in GaAs devices and the Cu/TaN films can be used for the backside copper metallization of GaAs MESFETs
Keywords :
Auger electron spectroscopy; III-V semiconductors; Schottky gate field effect transistors; X-ray diffraction; copper; diffusion barriers; gallium arsenide; semiconductor device metallisation; tantalum compounds; transmission electron microscopy; 300 degC; 40 nm; 550 degC; Auger electron spectroscopy; GaAs-TaN-Cu; MESFETs; RF characteristics; X-ray diffraction; backside metallization; cross-sectional transmission electron microscopy; device characteristics; diffusion barrier; electrical parameters; interfacial interaction; Copper; Electrons; Gallium arsenide; MESFETs; Metallization; Spectroscopy; Substrates; Thermal stresses; X-ray diffraction; X-ray scattering;
Journal_Title :
Electron Devices, IEEE Transactions on
