Lithography using interface reaction
View Patent ↗A method of forming a semiconductor structure by; forming a first mask trench in a first mask, where the first mask is on a substrate; forming a second mask in the first mask trench; and forming a third mask between the first mask and the second mask by reacting the first mask with the second mask, where the first mask, the second mask, and the third mask all have different etching properties and the third mask is a combination of the first mask and the second mask.
1. A method of forming a semiconductor structure comprising:
forming a first mask and a second mask having a vertical interface between the first mask and the second mask, the first mask is poly silicon and the second mask is poly germanium;
forming a third mask at the vertical interface between the first mask and the second mask using a diffusion process, wherein the third mask extends into a portion of the first mask and into a portion of the second mask, and wherein the third mask is poly silicon germanium;
forming a transfer pattern in a post-reaction layer, the post-reaction layer comprising the first mask, the second mask, and the third mask, and forming the transfer pattern further comprising:
forming a first pattern by removing a portion of the first mask selective to the second mask and the third mask; and
forming a second pattern by removing a portion of the second mask selective to the first mask and the third mask.
2. The method of claim 1 , further comprising:
polishing the second mask exposing the first mask.
3. The method of claim 1 , wherein the diffusion process includes an annealing process.
4. The method of claim 1 , wherein the diffusion process includes a plasma reaction.