Abstract. Ge₂Sb₂Te₅ films were deposited by RF magnetron sputtering on Si(100)/SiO₂ substrates. N⁺ ion was implanted into Ge₂Sb₂Te₅ films. Two obvious steps were observed in the resistance–temperature curve of the Ge₂Sb₂Te₅-N film with a minor nitrogen implant dose. The two steps may change into one step because the phase transition from FCC to hexagonal structure was suppressed by nitrogen implantation if the nitrogen implant dose is higher than 4.51 × 10¹⁶ cm⁻². The favourite nitrogen implant dose is about 6.44 × 10¹⁵ to 1.92 × 10¹⁶ cm⁻² in our study. This phenomenon is very important for multilevel storage. Three-level storage with Ge₂Sb₂Te₅-N media for chalcogenide random access memory (C-RAM) can be performed easily, and hence, the capacity of C-RAM will be dramatically increased.

Print publication: Issue 6 (June 2004)
Received 3 February 2004
Published 21 April 2004