Manufacturing method of charging capacity structure
A method of manufacturing a charging capacity structure includes steps of: forming a first oxide layer, a support layer and a second oxide layer on a substrate in sequence; forming a plurality of etching holes on the surface of the second oxide layer in a matrix to run through the substrate that are spaced from each other at a selected distance; forming a plurality of pillar layers in the etching holes; removing the second oxide layer by etching; forming an etching protection layer on the surfaces of the support layer and pillar tubes that is formed at a thickness one half of the spaced distance between the etching holes such that the pillar tubes at diagonal locations form a self-calibration hole; and finally removing the first oxide layer from the self-calibration hole by etching. Through the self-calibration hole, the invention needn't to provide extra photoresists to form holes.
1. A method of manufacturing a charging capacity structure, comprising the steps of:
S 1 : forming a first oxide layer, a support layer and a second oxide layer on a substrate in sequence;
S 2 : forming a plurality of etching holes on a surface of the second oxide layer in a matrix to run through the support layer, the first oxide layer and the substrate, the plurality of etching holes being spaced from each other at a selected distance;
S 3 : depositing a pillar layer on a wall surface of each of the plurality of etching holes;
S 4 : removing the second oxide layer to allow a portion of the pillar layer to protrude outside a surface of the support layer to form a plurality of pillar tubes;
S 5 : forming an etching protection layer on the surface of the support layer and on surfaces of the plurality of pillar tubes that is formed at a thickness equal to one half of a spaced distance between the etching holes, the pillar tubes at diagonal locations forming a self-calibration hole;
S 6 : removing the etching protection layer and the support layer in the self calibration hole via anisotropic etching;
S 7 : removing the first oxide layer via wet etching by injecting an etchant into the self-calibration hole to retain the pillar tubes formed from the pillar layer; and
S 8 : fabricating capacitors through the pillar tubes.
2. The method of claim 1 , wherein the first oxide layer and the second oxide layer at the step S 1 are made of a same material selected from the group consisting of silicon dioxide, borophosphosilicate glass and phosphorosilicate glass.
3. The method of claim 1 , wherein the first oxide layer at the step S 1 is formed at a thickness ranged from 500 nm to 3000 nm and the second oxide layer is formed at a thickness ranged from 100 nm to 600 nm.
4. The method of claim 1 , wherein the substrate and the support layer at the step S 1 are respectively made of silicon nitride.
5. The method of claim 1 , wherein the step S 3 further includes the steps of:
S 31 : forming the pillar layer on surfaces of the second oxide layer and the etching holes by deposition; and
S 32 : removing the pillar layer deposited on the surface of the second oxide layer.
6. The method of claim 1 , wherein the pillar layer at the step S 3 is made of titanium nitride.
7. The method of claim 1 , wherein the etching protection layer at the step S 5 is formed via atomic layer deposition.
8. The method of claim 1 , wherein the surfaces of the pillar tubes at the step S 8 are coated by a high dielectric layer, an electrode layer and a polycrystalline layer in sequence to form the capacitors.