Semiconductor Doping Profile Homogeneity via Ion Beam Alignment
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Solution Overview
Problem
Inhomogeneity in dopant concentration profiles in semiconductor devices leads to fluctuations in electrical characteristics and unwanted amorphization, which existing methods fail to adequately address.
Innovation Solution
A method involving precise alignment of the doping ion beam with the semiconductor substrate's crystal direction and controlled temperature management during ion implantation to achieve homogeneous doping profiles with reduced amorphization, using a target temperature range above 80°C for over 70% of the implant process time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional doping methods are used to achieve high dopant concentration, then doping depth is improved, but doping uniformity deteriorates due to inhomogeneity in dopant concentration profiles
Solution Approach 1:
The patent applies parameter changes by precisely controlling the ion beam direction to deviate less than ±0.5° from the main crystal direction and maintaining substrate temperature above 80°C during implantation. These parameter optimizations enable deeper doping while achieving uniform dopant concentration profiles, resolving the contradiction between doping depth and doping uniformity
Solution Approach 2:
The patent employs dynamic temperature control during the ion implantation process, maintaining the substrate temperature above 80°C throughout the implantation duration. This dynamic thermal management enables consistent dopant distribution at greater depths, simultaneously achieving both deep doping and uniform concentration profiles
2Quantity of substance
If high dose ion implantation is used to increase dopant concentration, then doping effectiveness is improved, but substrate amorphization increases
Solution Approach 1:
The patent changes the temperature parameter during ion implantation, maintaining substrate temperature above 80°C. This thermal parameter modification allows higher dopant concentrations to be achieved while preventing substrate amorphization, as the elevated temperature maintains crystalline structure stability during the implantation process
Solution Approach 2:
The patent applies preliminary heating of the substrate to above 80°C before and during ion implantation. This preliminary thermal preparation prevents amorphization by maintaining the crystal lattice in a stable state that can accommodate the implanted dopants without collapsing into an amorphous structure, even at high doping doses
3Ease of manufacture
If ion beam direction is not precisely aligned with crystal direction, then process tolerance is improved, but doping uniformity deteriorates
Solution Approach 1:
The patent optimizes the angular parameter by aligning the ion beam direction to deviate less than ±0.5° from the main crystal direction. This precise angular control achieves uniform dopant concentration profiles while maintaining practical manufacturability, resolving the contradiction between process tolerance and doping profile uniformity
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 results in more consistent and reliable semiconductor devices with improved doping profiles, reduced fluctuations in electrical characteristics, and minimized amorphization, enabling deeper and more uniform dopant concentrations.
Implementation Method 1
implanting doping ions into a semiconductor substrate
Implementation Method 2
controlling a temperature of the semiconductor substrate during the implantation of the doping ions so that the temperature of the semiconductor substrate is higher than 80° C. for more than 70% of an implant process time
Data Source
AI summary
A semiconductor device includes a device doping region of an electrical device arrangement disposed in a semiconductor substrate. A portion of the device doping region has a vertical dimension of more than 500 nm and a doping concentration of greater than 1*1015 dopant atoms per cm3. The doping concentration of the portion of the device doping region varies by less than 20% from a maximum doping concentration in the device doping region.