Plasma Treatment of Titanium Nitride Films for Low Resistance
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Solution Overview
Problem
The formation of titanium nitride films using titanium tetrachloride as a precursor gas results in residual chlorine and oxygen atoms, leading to increased electric resistance and deteriorated characteristics in semiconductor devices, particularly in DRAM capacitors, where high heat treatment can further degrade adjacent film characteristics and cause diffusion issues.
Innovation Solution
A substrate processing apparatus and method utilizing a plasma generation system that mixes nitrogen and hydrogen gases to activate and supply plasma to the titanium nitride film, reducing residual chlorine and oxygen atoms while improving oxidation resistance without deteriorating adjacent film characteristics, using a processing chamber with a susceptor for heating and gas supply systems to control the plasma treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high heat treatment is applied to remove chlorine atoms from the titanium nitride film, then the electric resistance is reduced, but the characteristics of adjacent capacitor insulating film are deteriorated and diffusion occurs in source and drain regions
Solution Approach 1:
The patent changes the processing temperature parameter from high temperature (700-900°C) to low temperature (200-450°C) plasma treatment, enabling effective chlorine removal without causing diffusion or damaging adjacent films. This parameter change resolves the contradiction by achieving the desired purification effect through a different physical mechanism (plasma chemistry rather than thermal diffusion).
Solution Approach 2:
The patent replaces the thermal field (heat treatment) with a plasma field (electromagnetic field) to achieve chlorine atom removal. Instead of using high temperature thermal energy, the invention uses plasma activation to generate reactive species that chemically react with and remove chlorine impurities, thereby avoiding the harmful thermal effects on adjacent structures.
2Manufacturing precision
If high heat treatment is applied to remove chlorine atoms, then the electric resistance is reduced, but diffusion occurs in source and drain regions reducing device performance
Solution Approach 1:
The patent changes the processing temperature parameter from high temperature (700-900°C) to low temperature (200-450°C) plasma treatment, enabling effective chlorine removal without causing diffusion or damaging adjacent films. This parameter change resolves the contradiction by achieving the desired purification effect through a different physical mechanism (plasma chemistry rather than thermal diffusion).
Solution Approach 2:
The patent replaces the thermal field (heat treatment) with a plasma field (electromagnetic field) to achieve chlorine atom removal. Instead of using high temperature thermal energy, the invention uses plasma activation to generate reactive species that chemically react with and remove chlorine impurities, thereby avoiding the harmful thermal effects on adjacent structures.
3Reliability
If low temperature treatment is used to avoid deterioration of adjacent films, then the characteristics are maintained, but chlorine atoms cannot be sufficiently removed from the titanium nitride film
Solution Approach 1:
The patent replaces the thermal field (heat treatment) with a plasma field (electromagnetic field) to achieve chlorine atom removal. Instead of using high temperature thermal energy, the invention uses plasma activation to generate reactive species that chemically react with and remove chlorine impurities, thereby avoiding the harmful thermal effects on adjacent structures.
Solution Approach 2:
The patent changes the processing method from thermal-based to plasma-based, enabling effective chlorine removal at low temperatures through chemical reactions in the plasma environment. The plasma state provides high reactivity without high temperature, resolving the contradiction between removal efficiency and adjacent film protection.
4Ease of manufacture
If the titanium nitride film is formed using titanium tetrachloride as precursor gas, then the film can be formed by CVD or ALD, but residual chlorine and carbon atoms remain in the film increasing electric resistance
Solution Approach 1:
The patent replaces thermal field with plasma field to selectively remove residual chlorine and carbon atoms from the titanium nitride film after formation. The plasma treatment provides a gentle yet effective purification method that maintains film integrity while removing impurities, thus resolving the contradiction between ease of manufacture and film purity.
Solution Approach 2:
The patent applies plasma treatment as a preliminary or subsequent step to remove impurities before the film is used in the device. This preliminary purification action ensures that the titanium nitride film achieves the required purity level for low resistance applications, resolving the contradiction between manufacturing ease and film quality.
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
The method effectively reduces chlorine and oxygen residues in titanium nitride films, enhancing their oxidation resistance and reducing electric resistance, while maintaining the quality of adjacent films by controlling the plasma treatment temperature within a specific range to prevent diffusion and performance degradation.
Implementation Method 1
a plasma generation part for exciting the nitrogen atoms-containing gas and the hydrogen atoms-containing gas supplied into the processing chamber
Implementation Method 2
a substrate support part for supporting and heating the substrate in the processing chamber
Data Source
AI summary
A manufacturing method for a semiconductor device, that loads a substrate on which a film containing oxygen atoms, chlorine atoms, and metal atoms is formed into a processing chamber so as to be supported by a substrate support part. The substrate is heated by the substrate support part. The inside of the processing chamber is exhausted by a gas exhaust part while supplying nitrogen atoms-containing gas and hydorgen atoms-containing gas into the processing chamber by a gas supply part. A plasma generation part is then used to excite the nitrogen atoms-containing gas and the hydrogen atoms-containing gas supplied into the processing chamber.