Patent ID: 6855564
Filing Date: 2005-02-15
Classification: B82Y,G11C,H01L

Abstract:
1. A method for forming the magnetic random access memory comprising the steps of: etching a semiconductor substrate by photolithography using an active mask to form a circular pillar, the semiconductor having a top surface; forming a gate oxide layer on the entire top surface of the semiconductor substrate; performing ion implantation of a high concentration impurity on the substrate and on a top portion of the circular pillar by a drive-in process, thereby forming a drain junction region on the upper side of the circular pillar and a source junction region on the bottom of the circular pillar extending into the substrate surface; forming a first word line of a gate electrode by forming a planarized conductor layer for the gate electrode exposing the drain junction region and then patterning the planarized conductor layer; forming a planarized first interlayer insulation layer; forming a contact line contacting the drain junction region through the first interlayer insulation layer; forming a semi-magnetic layer, a pinned ferromagnetic layer, a tunnel junction layer, and a free ferromagnetic layer above the contact line; forming a magnetic tunnel junction cell by patterning the semi-magnetic layer, the pinned ferromagnetic layer, the tunnel junction layer, and the free ferromagnetic layer by photolithography using a magnetic tunnel junction cell mask; forming a planarized second interlayer insulation layer exposing the magnetic tunnel junction cell; forming a bit line contacting the free ferromagnetic layer; and forming a second word line over the magnetic tunnel junction cell and above the bit line.