Magnetic memory device having a plurality of magneto-resistance effect elements arranged in a matrix form and method for manufacturing the same
A magnetic memory device comprises a plurality of magneto-resistance effect elements arranged in a matrix form. The each of a plurality of magneto-resistance effect elements have a pattern shape which substantially internally touches an ellipse having major and minor axes of the magneto-resistance effect element as major and minor axes thereof and a pitch between the adjacent magneto-resistance effect elements in a direction of the major axis is longer than that in a direction of the minor axis.
1. A method of manufacturing a magnetic memory device comprising:
forming a material used to form magneto-resistance effect elements on a main surface of a semiconductor substrate,
forming a photoresist on the material used to form the magneto-resistance effect elements,
respectively forming opening portions in the photoresist in central portions of forming regions of every four adjacent magneto-resistance effect elements,
equally enlarging the opening portions by isotropically etching the opening portions and causing at least two end portions of the opening portion in a major axis direction and two end portions thereof in a minor axis direction to overlap with end portions of the adjacent opening portions in a major axis direction and end portions of the adjacent opening portions in a minor axis direction, and
forming a plurality of magneto-resistance effect elements by etching the material used to form the magneto-resistance effect elements with the remaining photoresist used as a mask.
2. A method of manufacturing a magnetic memory device according to claim 1 , further comprising forming first write wirings on a main surface of the semiconductor substrate before forming the material used to form the magneto-resistance effect elements.
3. A method of manufacturing a magnetic memory device according to claim 1 , further comprising forming an inter-level insulating film on the entire surface after the forming the plurality of magneto-resistance effect elements with the remaining photoresist used as the mask, and forming second write wirings to intersect with the first write wirings in portions of the inter-level insulating film which correspond to positions lying above the magneto-resistance effect elements.
4. A method of manufacturing a magnetic memory device comprising:
forming a material used to form magneto-resistance effect elements on a main surface of a semiconductor substrate,
forming a first hard mask member on an entire surface of the material used to form the magneto-resistance effect elements,
forming a second hard mask member on an entire surface of the first hard mask member,
forming a photoresist on an entire surface of the second hard mask member,
forming a first opening portion in the photoresist in each central position of forming regions of every four adjacent ones of the magneto-resistance effect elements by use of a rectangular mask pattern,
forming second opening portions in the second hard mask member by using the photoresist in which the first opening portions are formed as a mask,
removing the photoresist used as the mask,
equally enlarging the second opening portions by isotropically etching the second opening portions and causing at least two end portions of the second opening portion in a major axis direction and two end portions thereof in a minor axis direction to overlap with end portions of the adjacent second opening portions in a major axis direction and end portions of the adjacent second opening portions in a minor axis direction, and
forming a plurality of magneto-resistance effect elements having a hard mask layer by etching the first hard mask member and the material used to form the magneto-resistance effect elements with the remaining portion of the second hard mask member used as a mask.
5. A method of manufacturing a magnetic memory device according to claim 4 , further comprising forming first write wirings on a main surface of the semiconductor substrate before forming the material used to form the magneto-resistance effect elements.
6. A method of manufacturing a magnetic memory device according to claim 4 , further comprising forming an inter-level insulating film on the entire surface after the forming the plurality of magneto-resistance effect elements, and forming second write wirings to intersect with the first write wirings in portions of the inter-level insulating film which lie above the plurality of magneto-resistance effect elements having the hard mask layer.