Sti of a semiconductor device and fabrication method thereof
AssigneeUnited Microelectronics Corp.
InventorsShao-Ta Hsu, Neng-Kuo Chen, Teng-Chun Tsai
Life of this patent
Estimating the term…
Abstract
A method for filling silicon nitride materials into a trench includes providing a substrate having a plurality of trenches, performing a first deposition process to form a first silicon nitride layer in the trenches, and performing a second deposition process to form a second silicon nitride layer in the trenches. The reactant gas of the first deposition process has a first O3/TEOS flow ratio larger than a second O3/TEOS flow ratio of the reactant gas of the second deposition process.
Claims22
A method of filling silicon oxide layers into trenches comprising:
- providing a substrate having a plurality of trenches;
- performing a first deposition process by providing a reactant gas with a first ozone (O3)/tetra-ethyl-ortho-silicate (TEOS) flow ratio to form a first silicon oxide layer on a surface of the substrate and in the trenches;
- and
- performing a second deposition process by providing a reactant gas with a second O3/TEOS flow ratio to from a second silicon oxide layer above the first silicon nitride layer, the second O3/TEOS flow ratio being less than the first O3/TEOS flow ratio.
A method for fabricating a shallow trench isolation (STI), the method comprising:
- providing a substrate having a first trench and a second trench, a width of the first trench being less than a width of second trench;
- performing a first deposition process to form a first silicon oxide layer in the first and second trenches so that the first trench is completely filled with the first silicon oxide layer and the bottom and the sidewall of the second trench is covered by the first silicon oxide layer;
- and
- performing a second deposition process to form a second silicon oxide layer filling into the second trench and covering the first silicon oxide layer, the carbon concentration of the second silicon oxide layer is different from the carbon concentration of the first silicon oxide layer.
A semiconductor device, comprising:
- a semiconductor substrate;
- at least a first trench and a second trench positioned near a surface of the semiconductor substrate, a width of the first trench is smaller than a width of the second trench;
- a first silicon oxide layer completely filling the first trench and positioned on the surfaces of the bottom and the sidewall of the second trench;
- and
- a second silicon oxide layer positioned in the second trench and covering the first silicon oxide layer, the concentration of the first silicon oxide layer is different from the carbon concentration of the second silicon oxide layer.
Dependencies are inferred from the claim text.