Methods for bottom up fin structure formation
Embodiments described herein relate to substrate processing methods. The methods include forming a patterned hardmask material on a substrate, forming first mandrel structures on exposed regions of the substrate, and depositing a gap fill material on the substrate over the hardmask material and the first mandrel structures. The first mandrel structures are removed to expose second region of the substrate form second mandrel structures comprising the hardmask material and the gap fill material and fin structures are deposited on the substrate using the second mandrel structures as a mask.
1. A substrate processing method, comprising:
forming a patterned hardmask material on a substrate;
forming first mandrel structures on exposed first regions of the substrate;
depositing a gap fill material on the hardmask material and the first mandrel structures;
removing the first mandrel structures to expose second regions of the substrate and form second mandrel structures comprising the hardmask material and the gap fill material; and
forming fin structures on the second regions of the substrate using the second mandrel structures as a mask.
2. The method of claim 1 further comprising:
depositing a spacer material on the hardmask material and patterning the spacer material, wherein the spacer material pattern is transferred to the hardmask material to form the patterned hardmask material.
3. The method of claim 2 , wherein the patterning the spacer material comprises performing a self-aligned double patterning process, a self-aligned quadruple patterning process, or a directed self-assembly process.
4. The method of claim 1 further comprising:
etching the gap fill material after forming the fin structures.
5. The method of claim 1 , wherein the forming the fin structures comprises epitaxially depositing on the second regions of the substrate a material selected from the group consisting of silicon containing material, germanium containing material, silicon germanium containing materials, and III-V materials.
6. The method of claim 1 , further comprising:
performing a chemical mechanical polishing process to planarize the gap fill material prior to removing the first mandrel structures.
7. The method of claim 1 , wherein the hardmask material is a silicon oxide material or a silicon nitride material.
8. The method of claim 1 , wherein the forming the first mandrel structures comprises epitaxially depositing a III-V material on the exposed regions of the substrate.
9. The method of claim 8 , wherein the first mandrel structures are formed from a GaAs material.
10. The method of claim 1 , wherein depositing the gap fill material comprises performing a chemical vapor deposition process.
11. The method of claim 10 , wherein performing the chemical vapor deposition process comprises depositing a flowable silicon oxide material or a flowable silicon nitride material.
12. The method of claim 1 , wherein depositing the gap fill material comprises depositing an oxide containing material deposited by a spin on glass process.
13. The method of claim 1 , wherein the first mandrel structures extend a first distance above a top surface of the substrate of greater than about 80 nm.
14. The method of claim 13 , wherein the first distance is between about 100 nm and about 200 nm.
15. The method of claim 13 , wherein the second mandrel structures extend a second distance above the top surface of the substrate approximately equal to the first distance.
16. A substrate processing method, comprising:
forming a hardmask material on a substrate;
depositing a spacer material on the hardmask material;
patterning the spacer material;
transferring the pattern of the spacer material to the hardmask material by etching the hardmask material to expose regions of the substrate;
forming first mandrel structures on the exposed regions of the substrate;
depositing a gap fill material on the hardmask material and the first mandrel structures;
removing the first mandrel structures to expose second regions of the substrate and form second mandrel structures comprising the hardmask material and the gap fill material;
forming fin structures on the second regions using the second mandrel structures as a mask; and
recessing the gap fill material below a top surface of the fin structures.
17. The method of claim 16 , wherein the fin structures are formed by an epitaxial deposition process.
18. The method of claim 16 , wherein the fin structures are formed from a material selected from the group consisting of silicon containing material, germanium containing material, silicon germanium containing materials, and III-V materials.
19. The method of claim 16 , wherein the gap fill materials are recessed a distance of greater than about 80 nm from the top surface of the fin structures.
20. A substrate processing method, comprising:
forming a patterned hardmask material on a substrate;
forming III-V material first mandrel structures on exposed regions of the substrate, wherein the III-V material first mandrel structures extend a first distance of greater than about 80 nm above a top surface of the substrate;
depositing a flowable oxide gap fill material on the hardmask material and the III-V material first mandrel structures;
removing the III-V material first mandrel structures to expose second regions of the substrate and form second mandrel structures comprising the hardmask material and the flowable oxide gap fill material, wherein the second mandrel structures extend a second distance above the top surface of the substrate approximately equal to the first distance;
epitaxially depositing fin structures on the second regions of the substrate; and
etching the gap fill material after forming the fin structures.