Memory Characteristics of Capacitors with Poly-GaP Floating Gates

Abstract

We fabricated a capacitor with polycrystalline gallium phosphide (Poly-GaP), which has high thermal immunity for better CMOS compactness, as a floating gate. Using a phosphide beam flux, in a molecular beam epitaxy chamber, 0.5 mu m of Poly-GaP film was successfully grown on silicon at 250 degrees C. Its device characteristics were compared with capacitors that instead used Poly-GaAs and Poly-Si. It is revealed that the memory window for the capacitor with the Poly-GaP floating film is comparable to the Poly-GaAs one, and still shows approximately twice the value of the Poly-Si. Based on these results, we conclude that flash memory with a Poly-GaP floating material can provide not only a wider memory window due to significant traps in III-V compounds, but also thermal immunity of the GaP material, which can be applied for 2D scaled flash memory.