SEMICONDUCTOR MEMORY DEVICE AND METHOD FOR MANUFACTURING SAME
First Claim
1. A semiconductor memory device comprising:
- a substrate;
a plurality of multilayer bodies stacked on the substrate, each of multilayer body including a plurality of dielectric films and a plurality of electrode films that are alternately layered, and having an end portion of a staircase shape;
a plurality of interlayer dielectric films provided around the respective multilayer bodies; and
a plurality of contacts buried so as to penetrate through the plurality of interlayer dielectric films and connected to respective end portions of the electrode films,the contact having a step difference at a position that is located between the interlayer dielectric films.
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Accused Products
Abstract
A first multilayer body is formed by alternately layering dielectric films and electrode films on a substrate. Then, an end portion of the first multilayer body is processed into a staircase shape, and a first interlayer dielectric film is formed around the first multilayer body. Next, a plurality of contact holes having a diameter decreasing downward are formed in the first interlayer dielectric film so that the contact holes reach respective end portions of the electrode films. Then, a sacrificial material is buried in the contact holes. Next, a second multilayer body is formed immediately above the first multilayer body, and a second interlayer dielectric film is formed around the second multilayer body. Thereafter, a plurality of contact holes having a diameter decreasing downward are formed in the second interlayer dielectric film to communicate with the respective contact holes formed in the first interlayer dielectric film. Then, the sacrificial material is removed and a contact is buried inside the contact holes. The contact has a step difference.
256 Citations
20 Claims
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1. A semiconductor memory device comprising:
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a substrate; a plurality of multilayer bodies stacked on the substrate, each of multilayer body including a plurality of dielectric films and a plurality of electrode films that are alternately layered, and having an end portion of a staircase shape; a plurality of interlayer dielectric films provided around the respective multilayer bodies; and a plurality of contacts buried so as to penetrate through the plurality of interlayer dielectric films and connected to respective end portions of the electrode films, the contact having a step difference at a position that is located between the interlayer dielectric films. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for manufacturing a semiconductor memory device, comprising:
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forming a first multilayer body by alternately layering a plurality of dielectric films and a plurality of electrode films on a substrate; processing an end portion of the first multilayer body into a staircase shape; forming a first interlayer dielectric film around the first multilayer body; forming a first contact hole having a diameter decreasing downward in the first interlayer dielectric film so that the first contact hole reaches an end portion of the electrode film; burying a sacrificial material in the first contact hole; forming a second multilayer body by alternately layering a plurality of dielectric films and a plurality of electrode films immediately above the first multilayer body; forming a second interlayer dielectric film around the second multilayer body; forming a second contact hole having a diameter decreasing downward in the second interlayer dielectric film so that the second contact hole reaches the first contact hole; removing the sacrificial material; and burying a contact inside the first contact hole and the second contact hole. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification