Etching method
An etching method including the following steps is provided. A substrate is provided first. A first region and a second region adjacent to the first region are defined on the substrate. A material layer is formed on the substrate. A pattern mask is formed on the material layer. The patterned mask includes a first part covering the material layer on the first region and a second part including a lattice structure. The lattice structure includes a plurality of openings and a plurality of shielding parts. Each opening exposes a part of the material layer on the second region. Each shielding part is located between the openings adjacent to one another. Each shielding part covers a part of the material layer on the second region. An isotropic etching process is then performed to remove the material layer exposed by the openings and the material layer covered by the shielding parts.
1. An etching method, comprising:
providing a substrate, wherein a first region and a second region adjacent to the first region are defined on the substrate, and the substrate further comprises conductive lines located in the second region;
forming a material layer on the substrate, wherein the material layer is formed covering the conductive lines in the second region, and the material layer is partly located between the conductive lines;
forming a patterned mask on the material layer, wherein a part of the material layer is located between the patterned mask and the each of the conductive lines in a vertical direction, and the patterned mask comprises:
a first part covering the material layer on the first region; and
a second part located corresponding to the second region, wherein the second part comprises a lattice structure, and the lattice structure comprises:
openings, wherein each of the openings exposes a part of the material layer on the second region, and each of the openings is located corresponding to a part of at least one of the conductive line in the vertical direction; and
shielding parts, wherein each of the shielding parts is located between the openings adjacent to one another, and each of the shielding parts covers at least a part of the material layer located between two of the conductive lines adjacent to each other; and
performing an isotropic etching process to remove the material layer exposed by the openings and the material layer covered by the shielding parts.
2. The etching method according to claim 1 , wherein the material layer covered by the shield parts is completely removed by a lateral etching of the isotropic etching process.
3. The etching method according to claim 1 , wherein each of the openings is elongated in a first direction, and the openings are repeated arranged in a second direction.
4. The etching method according to claim 1 , wherein the openings are arranged in a first direction and a second direction for forming an array configuration.
5. The etching method according to claim 1 , wherein each of the openings is located corresponding to a part of more than one of the conductive lines in the vertical direction.
6. The etching method according to claim 1 , wherein each of the shielding parts covers more than one of the conductive lines and the material layer located between the conductive lines covered by the shielding part.
7. The etching method according to claim 1 , wherein each of the conductive lines is elongated in a first direction, and the conductive lines are repeatedly arranged in a second direction.
8. The etching method according to claim 1 , wherein each of the conductive line comprises a bit line.
9. The etching method according to claim 8 , wherein the second region comprises a memory cell region, and the first region comprises a peripheral circuit region.
10. The etching method according to claim 9 , wherein the substrate further comprises gate structures located in the first region, and the material layer comprises a spacer material layer conformally formed on the conductive lines and the gate structures.