Monolithic PIN Diode Limiters With Multi-Depth Intrinsic Regions
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Solution Overview
Problem
Current design and fabrication techniques for PIN diodes limit the realization of diodes with different intrinsic region thicknesses on a single silicon wafer, necessitating the use of discrete diodes from multiple wafers for multistage limiters, which compromises reliability, RF performance, and cost.
Innovation Solution
A monolithic semiconductor structure with PIN diodes of varying intrinsic region thicknesses is developed, where multiple P-type regions are formed to different depths in a single intrinsic layer, allowing for the integration of diodes with different thicknesses on a single silicon wafer, enhancing reliability and RF performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If discrete diodes from multiple wafers are used for multistage limiters, then diodes with different intrinsic region thicknesses can be realized, but reliability and RF performance are compromised
Solution Approach 1:
The patent merges multiple diode structures with different intrinsic region thicknesses onto a single semiconductor wafer, creating a monolithic multistage limiter. This integration eliminates the need for discrete diodes from multiple wafers, thereby improving reliability while maintaining the ability to realize different intrinsic region thicknesses through selective doping processes.
Solution Approach 2:
The patent applies local quality by creating regions with different doping concentrations and intrinsic layer thicknesses in specific areas of the semiconductor wafer. Different portions of the wafer are doped to form diodes with tailored characteristics, allowing each diode region to have optimized properties for its specific function in the multistage limiter.
2Manufacturing precision
If discrete diodes from multiple wafers are used for multistage limiters, then diodes with different intrinsic region thicknesses can be realized, but cost increases
Solution Approach 1:
The patent combines multiple diode fabrication processes into a single wafer manufacturing cycle. By integrating the formation of multiple diode structures with different intrinsic region thicknesses into one monolithic device, the patent eliminates the need for separate wafer processing and assembly steps, thereby reducing manufacturing cost while maintaining precise control over intrinsic region thickness.
Solution Approach 2:
The patent creates a universal semiconductor wafer structure that can produce multiple types of diodes with different characteristics from a single substrate. This multi-functional approach allows one wafer to serve the purpose of multiple wafers, reducing material costs and simplifying the manufacturing process.
3Reliability
If multiple P-type regions are formed to different depths in a single intrinsic layer, then monolithic integration is achieved, but device complexity increases
Solution Approach 1:
The patent segments the doping process into multiple sequential steps, where different P-type regions are formed to different depths in the intrinsic layer through controlled ion implantation or diffusion. Each doping step targets specific depth ranges, allowing precise control over the vertical profile of dopant concentration while maintaining a systematic fabrication approach.
Solution Approach 2:
The patent utilizes parameter changes in the doping process, such as varying ion implantation energy, doping concentration, and thermal diffusion conditions, to achieve different P-type region depths from a single intrinsic layer. By adjusting these parameters across different processing steps, the patent creates a complex vertical doping profile without requiring complex device structures.
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 monolithic approach improves the reliability, RF performance, size, and cost of multistage limiters by enabling the integration of diodes with different intrinsic region thicknesses on a single substrate, overcoming the limitations of discrete diode solutions.
Implementation Method 1
A first diode includes a first doped region formed to a first depth into an intrinsic layer of a semiconductor structure. A second diode includes a second doped region formed to a second depth into the intrinsic layer of the semiconductor structure.
Data Source
AI summary
A number of diode limiter semiconductor structures are described. The diode limiters can include a hybrid arrangement of diodes with different intrinsic regions, all formed over the same semiconductor substrate. In one example, a diode limiter includes a first diode having a first doped region formed to a first depth into an intrinsic layer of a semiconductor structure, a second diode having a second doped region formed to a second depth into the intrinsic layer of the semiconductor structure, and at least one passive component. The first diode includes a first effective intrinsic region of a first thickness, the second diode includes a second effective intrinsic region of a second thickness. The first thickness is greater than the second thickness. The passive component is over the intrinsic layer and electrically coupled as part of the diode limiter.