SOI RF Device Layout With Defect-Rich Regions for Better Linearity
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Solution Overview
Problem
Radio frequency devices manufactured on silicon on insulator substrates face challenges in achieving improved linearity due to parasitic capacitances and charge carrier formation, which existing technologies have not adequately addressed.
Innovation Solution
The method involves forming radio frequency devices on silicon on insulator substrates with undoped silicon filler regions and polysilicon filler regions positioned differently, along with ion implantation to create defect-rich regions, which reduces free charge carriers and enhances linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing methods are used on silicon on insulator substrates, then radio frequency devices can be produced, but parasitic capacitances and free charge carriers degrade linearity
Solution Approach 1:
The patent extracts and removes harmful free charge carriers from the insulation region through selective ion implantation and thermal processing. By creating defect-rich regions that act as carrier traps, the method extracts unwanted charge carriers that would otherwise form parasitic capacitances and degrade RF device linearity.
Solution Approach 2:
The patent converts the harmful effect of ion implantation (which can create free charge carriers) into a beneficial process. By carefully controlling the ion implantation parameters and subsequent thermal processing, the method creates defect-rich regions that trap charge carriers, thereby converting what would be harmful free carriers into beneficial trapped states that reduce parasitic capacitance.
2Manufacturing precision
If doping is used to modify regions, then electrical properties can be controlled, but free charge carriers increase and degrade linearity
Solution Approach 1:
The patent changes the fundamental parameter approach from chemical doping to physical defect creation. Instead of introducing dopant atoms that create free charge carriers, the method uses ion implantation to create crystal defects that trap carriers. This parameter change allows electrical property control without increasing free charge carrier concentration.
Solution Approach 2:
The patent applies local quality by creating spatially differentiated regions with different defect concentrations. The ion implantation is selectively applied to specific areas around the RF device, creating local defect-rich regions that trap charge carriers where needed, while leaving other regions unaffected. This localized approach provides precise control over where charge carrier trapping occurs.
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 effectively reduces parasitic capacitances and improves linearity by minimizing free charge carriers, thereby meeting stringent specification requirements for next-generation radio frequency devices.
Implementation Method 1
ion implantation to create defect-rich regions, which reduces free charge carriers and enhances linearity
Data Source
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AI summary
In an embodiment, a radio frequency device (26-29) is formed at an active layer (24) of a silicon on insulator substrate. An ion implantation (25) is performed around the radio frequency device to generate a defect-rich region.