Hafnium Amide Complex Purification via Reduced-Pressure Distillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing hafnium amide complexes for semiconductor film formation face challenges in achieving high yield, purity, and controlling zirconium concentration, which affects the reliability of hafnium-containing oxide films.
Innovation Solution
A method involving reduced-pressure distillation after reacting lithium alkylamide with a tertiary hafnium alkoxide complex to produce a hafnium amide complex, effectively reducing zirconium concentration and improving yield, using specific alkoxide complexes and reaction conditions to isolate the hafnium amide complex with low lithium alkoxide impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hafnium tetrachloride and lithium alkylamide are reacted in an organic solvent to produce hafnium amide complex, then the hafnium amide complex can be synthesized, but the zirconium concentration in the product remains high (1000-5000 mass ppm)
Solution Approach 1:
The patent applies extraction by performing reduced-pressure distillation to separate and remove zirconium-containing impurities from the hafnium amide complex product. The distillation process extracts the harmful zirconium component (reducing concentration from 1000-5000 mass ppm to below 10 mass ppm) while retaining the desired hafnium amide complex, thereby resolving the contradiction between maintaining high zirconium concentration (easier synthesis) and achieving low zirconium concentration (higher device reliability).
2Productivity
If conventional production methods are used for hafnium amide complex, then the production process is simple, but the yield is low and the process is not economically viable
Solution Approach 1:
The patent applies preliminary action by performing reduced-pressure distillation as a post-synthesis purification step to remove by-products and impurities. This preliminary separation action increases the overall production yield by recovering pure hafnium amide complex that would otherwise be lost in conventional methods, while adding only one additional operation step to the synthesis process, thus improving productivity without excessive complexity.
3Manufacturing precision
If high purity hafnium amide complex is required for semiconductor film formation, then the film quality is ensured, but the production cost increases due to complex purification processes
Solution Approach 1:
The patent applies parameter changes by utilizing reduced-pressure conditions during distillation to selectively vaporize and remove impurities based on their volatility differences. By changing the pressure parameter during the purification process, the method achieves high purity hafnium amide complex (reducing zirconium to below 10 mass ppm) through a relatively simple single-step distillation process rather than multiple complex purification operations, thus ensuring film purity without excessive process complexity.
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 enables the production of hafnium amide complexes with significantly reduced zirconium concentration, enhancing the reliability of hafnium-containing oxide films and improving the semiconductor film formation process by ensuring high purity and economic viability.
Implementation Method 1
a hafnium film formation raw material high in vapor pressure is required
Implementation Method 2
a physical vapor-phase growth process (Physical Vapor Deposition, abbreviated hereinafter as PVD)
Implementation Method 3
a chemical vapor-phase growth process (Chemical Vapor Deposition, abbreviated hereinafter as CVD)
Implementation Method 4
reduced-pressure distillation after reacting lithium alkylamide with a tertiary hafnium alkoxide complex
Data Source
AI summary
Disclosed is a method of producing a hafnium amide complex represented by general formula: Hf(NR4R5)4, characterized by comprising: carrying out a reduced-pressure distillation after a lithium alkylamide represented by general formula: Li(NR4R5) is added to and allowed to react with a tertiary hafnium alkoxide complex represented by general formula: Hf[O(CR1R2R3)]4. (In the formulas, R1, R2 and R3 independently represent either a phenyl group, a benzyl group, or a primary, secondary or tertiary alkyl group having a carbon number 1-6; and R4 and R5 independently represent either a methyl group or an ethyl group; however, a case where all of R1, R2 and R3 are methyl groups, and a case where one of R1, R2 and R3 is an ethyl group and the other two are methyl groups are excluded.)