Patent ID: 9166165
Filing Date: 2015-10-20
Classification: H01L

Abstract:
1. A method of forming a memory cell, the method comprising: forming a bottom insulating layer above a substrate; forming a bottom electrode within the bottom insulating layer; forming a first intermediate insulating layer above the bottom insulating layer; forming a second intermediate insulating layer above the first intermediate insulating layer, the second intermediate insulating layer selectively etchable from the first intermediate insulating layer; forming a top insulating layer above the second intermediate insulating layer; defining a via through the top insulating layer and the second intermediate insulating layer above the bottom electrode, the via and bottom electrode being separated by the first intermediate insulating layer; depositing a sacrificial spacer layer within the via, the conformality of deposition of the sacrificial spacer layer being such that a cavity is formed by and is surrounded by the sacrificial spacer layer, the cavity positioned above the first intermediate insulating layer; and etching the sacrificial spacer layer to form a funnel-shaped sacrificial spacer having a curved bottom portion and a vertical top portion above the first intermediate insulating layer, the curved bottom portion is contained entirely within the second intermediate insulating layer and the vertical top portion directly contacts the second intermediate insulating layer and the top insulating layer, the funnel-shaped sacrificial spacer including a channel having a smaller diameter than a diameter of the via; defining a pore through the first intermediate insulating layer below the funnel-shaped sacrificial spacer and above the bottom electrode such that the channel continues through the first intermediate insulating layer to the bottom electrode; removing the funnel-shaped sacrificial spacer; depositing phase change material in the pore, the phase change material filling the entire pore; and forming an upper electrode above the phase change material.