Atomic Layer Etching with Dual-Temperature Surface Modification
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Solution Overview
Problem
Current atomic layer etching processes in semiconductor manufacturing apply thermal shock due to high-temperature operations, leading to changes in crystal structure and electrical properties of materials like ZrO2 and TiN, which results in defects such as hillocks and non-volatile reaction by-products.
Innovation Solution
A method and apparatus for atomic layer etching that control the substrate temperature in two distinct stages: a first temperature for surface modification using a modifying gas and a second temperature for etching, allowing for minimal energy input and a ligand exchange reaction to occur, thereby preventing thermal stress and enabling precise thickness removal without altering the material's properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature is maintained during both modifying and removing steps, then the etching process can proceed efficiently, but thermal shock causes changes in crystal structure and electrical properties of the target material
Solution Approach 1:
The patent applies dynamics by making the substrate temperature variable rather than constant. The temperature is dynamically adjusted between a first temperature during the modifying step and a second temperature during the removing step. This dynamic temperature control allows the process to optimize etching efficiency at one temperature while preventing thermal shock at another temperature, thereby resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent changes the temperature parameter between different process steps. Specifically, it maintains the substrate at a first temperature during the modifying step and changes it to a second temperature during the removing step. This parameter change enables the process to achieve both high etching efficiency and material property stability by matching temperature conditions to the specific requirements of each process step.
2Productivity
If thermal shock is applied to remove material quickly, then productivity increases, but defects such as hillocks and non-volatile reaction by-products are generated
Solution Approach 1:
The patent uses dynamic temperature adjustment to balance material removal rate and surface quality. By changing the substrate temperature between process steps rather than maintaining a constantly high temperature, the method achieves efficient material removal while preventing thermal shock-induced defects, thus resolving the contradiction between productivity and manufacturing precision.
Solution Approach 2:
The patent implements periodic action through alternating temperature conditions in a cyclic manner. The substrate temperature is periodically changed between a first temperature during modifying and a second temperature during removing. This periodic temperature variation enables controlled material removal with high precision by preventing cumulative thermal shock effects that would otherwise generate surface defects.
3Device complexity
If constant high temperature is used for both modifying and removing steps, then process simplicity is maintained, but ligand exchange reaction cannot occur and precise thickness removal is compromised
Solution Approach 1:
The patent changes the temperature parameter between process steps to enable precise thickness removal. By maintaining the substrate at a first temperature during modifying and changing it to a second temperature during removing, the process facilitates ligand exchange reactions and achieves atomic-layer precision. This parameter change approach balances the added control complexity with the significant improvement in manufacturing precision.
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 approach allows for precise control of the etching process, preventing thermal stress-induced defects and ensuring the material's properties remain intact, enabling efficient and accurate removal of target films by controlling temperatures in the modifying and etching steps.
Implementation Method 1
a modifying step of controlling the substrate at a first temperature and modifying a surface layer of the material to be removed by supplying a modifying gas to the substrate
Implementation Method 2
an etching step of controlling the substrate at a second temperature different from the first temperature and removing the modified surface layer by supplying an etching gas to the substrate, wherein a surface layer of a material to be etched is modified in any one of the first processing space and the second processing space, and the modified surface layer is etched in the other processing space
Implementation Method 3
a plasma generator activated in a plasma atmosphere and configured to radicalize the process gas provided from a gas providing unit
Data Source
AI summary
A method for atomic layer etching may include a step of providing a substrate on which a material to be etched is formed, a modifying step of controlling the substrate at a first temperature and modifying a surface layer of the material to be removed by supplying a modifying gas to the substrate, and an etching step of controlling the substrate at a second temperature different from the first temperature and removing the modified surface layer by supplying an etching gas to the substrate.