Method with high gapfill capability for semiconductor devices
View Patent ↗A method of performing an STI gapfill process for semiconductor devices is provided. In a specific embodiment of the invention, the method includes forming an stop layer overlying a substrate. In addition, the method includes forming a trench within the substrate, with the trench having sidewalls, a bottom, and a depth. The method additionally includes forming a liner within the trench, the liner lining the sidewalls and bottom of the trench. Furthermore, the method includes filling the trench to a first depth with a first oxide. The first oxide is filled using a spin-on process. The method also includes performing a first densification process on the first oxide within the trench. In addition, the method includes depositing a second oxide within the trench using an HDP process to fill at least the entirety of the trench. The method also includes performing a second densification process on the first and second oxides within the trench.
1. A method for processing semiconductor devices comprising:
forming a trench within a substrate, the trench having a total height;
filling 40% or less of the total height of the trench with a first oxide without any subsequent etching, the first oxide being filled using a spin-on process;
performing a first densification process on the first oxide within the trench;
depositing a second oxide within the trench using an HDP process to fill at least the entirety of the trench; and
performing a second densification process on the first and second oxides within the trench.
2. The method of claim 1 further comprising:
forming a stop layer overlying the substrate; and
forming a liner within the trench, the liner lining sidewalls and bottom of the trench.
3. The method of claim 2 further comprising:
performing a planarization process; and
removing the stop layer.
4. The method of claim 2 wherein the stop layer is silicon nitride.
5. The method of claim 3 further comprising removing a portion of the stop layer following the deposition of oxide within the trench using the HDP process.
6. The method of claim 1 further comprising forming a pad oxide layer overlying the substrate.
7. The method of claim 1 wherein the trench has a width of 0.10 μm of smaller.
8. The method of claim 1 wherein the trench has an aspect ratio of 5:1 or greater.
9. The method of claim 1 wherein one or more of the densification processes may be performed in an N2 and/or O2 ambient to produce an oxide having a compressive stress.
10. The method of claim 1 wherein one or more of the densification processes may be performed in an H2O ambient to produce an oxide having a tensile stress.
11. The method of claim 1 wherein the first densification process is performed at a temperature between 400-800 degrees C. for a duration between 30 seconds to 30 minutes.
12. The method of claim 1 wherein the second densification process is performed at a temperature between 850-1100 degrees C. for a duration between 30 seconds to 30 minutes.