Method and system for three-dimensional (3D) structure fill
Embodiments include methods and systems of 3D structure fill. In one embodiment, a method of filling a trench in a wafer includes performing directional plasma treatment with an ion beam at an angle with respect to a sidewall of the trench to form a treated portion of the sidewall and an untreated bottom of the trench. A material is deposited in the trench. The deposition rate of the material on the treated portion of the sidewall is different than a second deposition rate on the untreated bottom of the trench. In one embodiment, a method includes depositing a material on the wafer, filling a bottom of the trench and forming a layer on a sidewall of the trench and a top surface adjacent to the trench. The method includes etching the layer with an ion beam at an angle with respect to the sidewall.
1. A method of filling a trench in a semiconductor wafer, the method comprising:
performing a first directional plasma treatment with a first ion beam at a first angle with respect to a sidewall of the trench to form a treated portion of the sidewall and an untreated bottom of the trench;
depositing a material in the trench directly on the treated portion of the sidewall and the untreated bottom of the trench, wherein a deposition rate of the material on the treated portion of the sidewall is different than a second deposition rate on the untreated bottom of the trench, and wherein the material is deposited using a technique selected from the group consisting of chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), and atomic layer deposition (ALD); and
performing a second directional plasma treatment with a second ion beam at a second angle with respect to a sidewall of the trench to perform an angled ion beam etching upon the deposited material.
2. The method of claim 1 , wherein performing the first directional plasma treatment comprises generating the ion beam at the angle in a range of 1-85 degrees with respect to the sidewall.
3. The method of claim 1 , wherein the trench has an aspect ratio of approximately 5 to 1, and wherein performing the first directional plasma treatment with the ion beam at the angle comprises treating a top 20-30% of the sidewall.
4. The method of claim 1 , wherein the trench has an aspect ratio of approximately 4 to 1, and wherein performing the first directional plasma treatment with the ion beam at the angle comprises treating at least a top 80% of the sidewall.
5. The method of claim 1 , wherein performing the first directional plasma treatment further comprises generating a second ion beam at a second angle with respect to a second sidewall of the trench to form a second treated portion of the second sidewall.
6. The method of claim 1 , wherein performing the first directional plasma treatment damages a surface of the treated portion of the sidewall, and wherein the deposition rate of the material on the treated portion is slower than the second deposition rate on the untreated bottom of the trench.
7. The method of claim 1 , wherein performing the first directional plasma treatment comprises generating the ion beam with an ion species to change a dopant or impurity concentration, dopant or impurity profile, or hydrophobicity of a surface of the treated portion of the sidewall.
8. The method of claim 1 , wherein the deposition rate of the material on the treated portion is faster than the second deposition rate on the untreated bottom of the trench, and wherein depositing the material in the trench comprises forming a void at the bottom of the trench.
9. The method of claim 1 , further comprising:
supporting the semiconductor wafer over a stage;
rotating the stage; and
performing the first directional plasma treatment with the second ion beam at the second angle with respect to a second sidewall of the trench to form a second treated portion of the second sidewall.
10. The method of claim 1 , wherein depositing the material comprises depositing a dielectric or metal.