CVD/ALD Precursors
Development of high-purity precious metal precursors for next-generation semiconductors
Amid the semiconductor industry’s requirement for further miniaturization and improved durability, TANAKA seeks to reduce costs and achieve higher quality by improving the film deposition speed of ruthenium (Ru) precursors, and will contribute to the development of new advanced technologies enabled by semiconductors.
CVD = Chemical Vapor Deposition
ALD = Atomic Layer Deposition
Development and Provision of Precursors
We develop various CVD/ALD precursors, mainly Ru-based. For this purpose, we have CVD systems for producing semiconductor thin films and a variety of analytical instruments (FE-SEM, AFM, XRF, etc.) to evaluate them and provide purpose-specific precursor solutions.
■Examples of precursor products (Ru)
| Product Name | Appearance |
|---|---|
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DCR High-purity precursor for Ru film deposition |
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Rupta Oxygen-free precursor for Ru film deposition |
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TRuST High vapor pressure precursor for Ru film deposition |
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As semiconductors have evolved, there are increasing expectations for Ru to promote further miniaturization of semiconductors because of its lower resistance and higher durability. With its superior characteristics, Ru is also being considered for use in transistor gate electrodes and DRAM capacitor electrodes.
High vapor pressure precursor for Ru film deposition：TRuST
Using Liquid Ruthenium Precursor to Achieve World’s Highest Vapor Pressures
CVD/ALD Precursors with a vapor pressure 100 times* higher than that of conventional liquid Ru precursors.
This technologies will help increase performance and reduce energy consumption for the semiconductor devices used in smartphones, computers, and the data centers where demand is to grow well into the future.
* Experimental value obtained through TANAKA’s internal evaluation at room temperature
■Features
- High vapor pressure even at around room temperature
- Easily decomposes in reaction gas (hydrogen, oxygen, etc.), allowing the deposition of Ru films with low resistance
- Good adsorption efficiency on substrate surface due to its small molecules, achieving high film deposition speed
- Excellent step coverage that allows homogeneous film deposition even to the depths of miniature structures with high aspect ratios
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Comparison of vapor pressures of precursors
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Thin Ru film formed by ALD using TRuST
■Two-stage ALD process using TRuST
Prevents oxidation of substrates and achieves ultra-thin films of high quality and low resistance through a two-stage ALD process using oxygen and hydrogen
Two-stage film deposition process using TRuST
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First stage: Ru film deposition using H2
Reduces the risk of base film surface oxidation by using hydrogen film deposition -
Second stage: Ru film deposition using O2
High-purity film deposition that maintains Ru purity at almost 100% using oxygen film deposition -
By forming the base first using hydrogen film deposition, the Ru film on top of the base created using oxygen film deposition will be smooth and dense, achieving a lower resistance than before
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First stage: Ru film deposition using H2
Reduces the risk of base film surface oxidation by using hydrogen film deposition -
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Second stage: Ru film deposition using O2
High-purity film deposition that maintains Ru purity at almost 100% using oxygen film deposition -
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By forming the base first using hydrogen film deposition, the Ru film on top of the base created using oxygen film deposition will be smooth and dense, achieving a lower resistance than before
- The two-stage film deposition process allows deposition of dense, low-resistance Ru films, including ultra-thin films.
- As the stages are conducted using the same raw materials and film deposition temperature, this process can contribute toward reducing the process costs and capital investment costs.
Cross-sectional SEM image of
two-stage film deposition
