Substrate Film Deposition Sequencing for Deep Groove Step Coverage
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Solution Overview
Problem
The increasing aspect ratio of grooves on substrates in 3D NAND structures poses a challenge for achieving effective step coverage performance during film formation, necessitating improved gas supply to the bottom of these structures.
Innovation Solution
A method involving sequential supply of a precursor gas containing a first element and halogen, followed by a first reducing gas, then a second reducing gas, with specific timing and sequencing to form a film on the substrate, including starting the first reducing gas during precursor gas supply and continuing after precursor gas cessation without purging, and finally applying the second reducing gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional film formation methods are used, then the process is simple, but the step coverage performance deteriorates in deep grooves
Solution Approach 1:
The gas supply process is segmented into multiple distinct phases: precursor gas supply, first reducing gas supply, second reducing gas supply, and purge gas supply. Each phase serves a specific function in achieving uniform step coverage, with the precursor gas providing material, the reducing gases facilitating reaction and coverage, and the purge gas removing excess materials.
Solution Approach 2:
The patent employs periodic, sequential gas supply actions rather than continuous supply. The gas supply is divided into repeated cycles of precursor gas, first reducing gas, second reducing gas, and purge gas, where each gas type is supplied in a specific sequence and timing pattern to achieve uniform deposition throughout the groove structure.
2Manufacturing precision
If gas is supplied continuously, then the process is simple, but the film coverage becomes non-uniform in deep grooves
Solution Approach 1:
The precursor gas is supplied in a preliminary phase before the reducing gases to pre-deposit material on the substrate surface and in grooves. This preliminary action ensures that material is available before the reducing gases arrive, facilitating uniform coverage. The timing is controlled so that the precursor gas supply ends just as the first reducing gas supply begins, optimizing the sequence.
Solution Approach 2:
The patent maintains continuous useful action by ensuring that one gas supply phase always begins as the previous phase ends, with no idle time between gas supply steps. The precursor gas supply ends exactly when the first reducing gas supply begins, and this continues through all phases, maintaining uninterrupted film formation activity throughout the process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enhances the step coverage performance of films on substrates by improving the continuity and coverage of the formed film, particularly in deep grooves, thereby enhancing the manufacturing process efficiency.
Implementation Method 1
supplying a precursor gas containing a first element and halogen to a substrate; supplying a first reducing gas to the substrate; supplying a second reducing gas to the substrate; forming a film containing the first element on the substrate
Data Source
AI summary
There is provided a technique that includes (a) supplying a precursor gas containing a first element and halogen to a substrate; (b) supplying a first reducing gas to the substrate; (c) supplying a second reducing gas to the substrate; and (d) supplying the precursor gas to the substrate, wherein the technique further includes: (e) starting (b) during (a) and ending (a) during (b); (f) performing (d) after (e) without purging between (e) and (d); (g) performing (c) after (f); and (h) forming a film containing the first element on the substrate by performing (e), (f), and (g) sequentially in this order a predetermined number of times.