Patent ID: 8377741

Claim:
A method, comprising: forming first and second phase change memory cells, the forming including: forming a first ovonic threshold switch layer; forming a first phase change layer on the first ovonic threshold switch layer; and forming a second ovonic threshold switch layer on the first phase change layer, the first and second ovonic threshold switch layers being separated by the first phase change layer; forming a first dielectric layer; forming first and third ovonic threshold switches from the first ovonic threshold switch layer in the first dielectric layer, the third ovonic threshold switch being spaced apart from the first ovonic threshold switch; forming first and second phase change regions from the first phase change layer, the first phase change region being on the first ovonic threshold switch and the second phase change region being on the third ovonic threshold switch; and forming second and fourth ovonic threshold switches from the second ovonic threshold switch layer, the second ovonic threshold switch being on the first phase change region and the fourth ovonic threshold switch being on the second phase change region.