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 (0.05–5 keV), 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 (4 sccm) and He (100 sccm) gases were flown to the plasma chamber, and a voltage of 4.5 kV was applied. After pulsed PIII process, furnace annealing was performed at 900 °C 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.