Semiconductor device manufacturing method, and semiconductor device
View Patent ↗A method of manufacturing a semiconductor device in which the formation of buried wiring is facilitated includes: forming columnar patterns, which are arranged in a two-dimensional array, and bridge patterns, which connect the columnar patterns in a column direction, on a main surface of a silicon substrate; injecting an impurity in a surface portion of each of the columnar patterns and bridge patterns and in surface portions of the silicon substrate, thereby forming impurity injection layers; forming a side wall on sides of the columnar patterns and bridge patterns; removing the impurity injection layer, which has been formed in the silicon substrate, with the exception of the impurity injection layer covered by the bottom portions of the side walls; removing the side walls by etch-back; and thermally oxidizing the surface portion of the bridge patterns and then etching away the same. Buried wiring extending in the column direction of the columnar patterns is formed within the silicon substrate.
1. A method of manufacturing a semiconductor device, comprising:
forming columnar patterns, which are arranged in a two-dimensional array, and bridge patterns, which connect the columnar patterns in a column direction, on a semiconductor substrate;
injecting an impurity in a top surface portion of each of the columnar patterns and bridge patterns and in exposed surface portions of the semiconductor substrate, thereby forming diffusion regions;
forming a side-wall oxide film that covers side surfaces of the columnar patterns and bridge patterns;
removing the diffusion region from the surface portions of the semiconductor substrate with the exception of the diffusion region covered by the side-wall oxide film; and
removing the side-wall oxide film;
wherein diffusion regions left on the semiconductor substrate are adopted as column wiring extending in the column direction.
2. The method according to claim 1 , further comprising the steps of:
oxidizing at least the bridge patterns by a thermal oxidation method following said removing the side-wall oxide film; and
removing the oxidized bridge patterns.
3. The method according to claim 2 , further comprising:
forming an oxide film that covers the columnar patterns and the surface portions of the silicon substrate following said removing the bridge patterns; and
forming row wiring, which extends in a row direction on side walls of the columnar patterns and surface of the silicon substrate, on the surface of the oxide film.
4. The method according to claim 1 , wherein at said forming the columnar patterns and bridge patterns, a first distance between the columnar patterns mutually adjacent in the column direction connected by the bridge patterns and a second distance between the columnar patterns mutually adjacent in the row direction are made approximately the same.
5. The method according to claim 1 , wherein at said forming the columnar patterns and bridge patterns, a first distance between the columnar patterns mutually adjacent in the column direction connected by the bridge patterns is made larger than a second distance between the columnar patterns mutually adjacent in the row direction.
6. The method according to claim 5 , wherein the columnar patterns mutually adjacent in the row direction are staggered with respect to the column direction by a distance less than the first distance.
7. The method according to claim 1 , wherein the semiconductor substrate is a silicon substrate.