Title :
Passivation of GaAs FET´s with PECVD silicon nitride films of different stress states
Author :
Chang, Edward Y. ; Cibuzar, Gregory T. ; Pande, Krishna P.
Author_Institution :
Unisys Corp., St. Paul, MN, USA
fDate :
9/1/1988 12:00:00 AM
Abstract :
The passivation of GaAs MESFETs with plasma-enhanced chemical-vapor-deposited (PECVD) silicon nitride films of both compressive and tensile stress is reported. Elastic stresses included in GaAs following nitride passivation can produce piezoelectric charge density, which results in a shift of MESFET characteristics. The shift of MESFET parameters due to passivation was found to be dependent on gate orientation. The experiments show that nitride of tensile stress is preferable for MESFETS with [011-bar] oriented gates. The shifts in VTH,IDSS, and GM of the devices before and after nitride passivation are less than 5% if the nitride of appropriate stress states are used for passivation. The breakdown voltage of the MESFETs after nitride deposition was also studied. It is found that the process with higher hydrogen incorporation tends to reduce the surface oxide and increase the breakdown voltage after nitride deposition. In addition, the passivation of double-channel HEMTs is reported for the first time
Keywords :
CVD coatings; III-V semiconductors; Schottky gate field effect transistors; dielectric thin films; electric breakdown of solids; field effect integrated circuits; gallium arsenide; high electron mobility transistors; integrated circuit technology; microwave integrated circuits; passivation; semiconductor technology; silicon compounds; stress effects; CVD coating; GaAs; H incorporation; III-V semiconductors; MESFETs; MMIC; PECVD; Si3N4; breakdown voltage; characteristics shift; compressive stress; double-channel HEMTs; elastic stresses; gate orientation; microwave IC; monolithic IC; nitride passivation; piezoelectric charge density; plasma-enhanced chemical-vapor-deposited; surface oxide reduction; tensile stress; FETs; Gallium arsenide; MESFETs; Passivation; Piezoelectric films; Plasma chemistry; Plasma properties; Semiconductor films; Silicon; Tensile stress;
Journal_Title :
Electron Devices, IEEE Transactions on
