Formation of Ge nanocrystals in a silicon dioxide layer using pulsed plasma-immersion ion implantation
Pulsed plasma-immersion ion implantation (PIII) or Pulsed PLAsma Doping (P2LAD) is known as a cost effective solution for ultra shallow junction formation due to its capability to implant doping species at ultra-low energies (0.055keV), the advantages of P2LAD, high concentration and sharp distribution of the implanted species, also make this technique a good candidate to fabricate nanocrystals (NCs) within silicon dioxide (SiO2) layer. In this work, we report Ge NC fabrication within a SiO2 layer by using the pulsed PIII technique for the first time. GeH4 (4sccm) and He (100sccm) gases were flown to the plasma chamber, and a voltage of 4.5kV was applied. After pulsed PIII process, furnace annealing was performed at 900C in nitrogen atmosphere for Ge agglomeration. By using such a process, we fabricated non-volatile memory devices and obtained relevant program/erase, retention, and cycling characteristics.
pulsed plasma-immersion ion implantation pulsed plasma doping nanocrystal memory germanium