Semiconductor Structure With Dielectric Isolation For Parasitic Capacitance
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Solution Overview
Problem
Semiconductor devices formed on conductive silicon substrates face challenges such as low quality factors, reduced operational frequencies, and parasitic capacitance due to parasitic capacitive coupling, which limits the performance of passive devices and power transistors in high-frequency applications.
Innovation Solution
A semiconductor structure is developed with a dielectric structure that surrounds and isolates active areas, reducing parasitic capacitance and increasing breakdown voltage, while also incorporating a dielectric platform with a low dielectric constant to minimize capacitive coupling and enhance thermal dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If passive devices are formed on or in close proximity to a conductive silicon substrate, then device integration is achieved, but parasitic capacitive coupling increases causing reduced quality factors and lower operational frequencies
Solution Approach 1:
An intermediate dielectric layer is introduced between the conductive silicon substrate and the passive devices. This dielectric layer acts as a mediator that reduces parasitic capacitive coupling while allowing the devices to remain integrated on the substrate, thus resolving the contradiction between integration and parasitic coupling.
Solution Approach 2:
The substrate surface is segmented into multiple isolation regions separated by dielectric material. This segmentation creates electrically isolated islands where passive devices can be formed with reduced parasitic coupling to the substrate, while maintaining overall device integration on the same substrate.
2Power
If power transistors are designed for high power output, then power delivery capability increases, but breakdown voltage requirements increase leading to larger device dimensions
Solution Approach 1:
The breakdown voltage parameter is increased through modified transistor design and dielectric layer optimization. By changing the electrical parameters (breakdown voltage) rather than simply scaling up physical dimensions, high power output is achieved with controlled device size.
Solution Approach 2:
A composite structure is formed combining the conductive silicon substrate with a dielectric layer of specific properties. This composite material system allows high power transistors to achieve both high breakdown voltage and compact dimensions by leveraging the complementary properties of the substrate and dielectric layer.
3Reliability
If dielectric structures are added to reduce parasitic capacitance, then quality factor and operational frequency improve, but device complexity and manufacturing steps increase
Solution Approach 1:
The dielectric layer is designed to serve multiple functions simultaneously: it reduces parasitic capacitive coupling, provides electrical isolation, and maintains mechanical support. This multi-functionality allows quality factor improvement without proportionally increasing structural complexity.
Solution Approach 2:
The isolation dielectric structures are merged with the existing device fabrication process flow. By integrating the dielectric layer formation into the standard manufacturing sequence rather than adding separate complex isolation steps, quality factor improvement is achieved with minimal increase in overall manufacturing 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
The solution effectively increases the quality factor of passive devices, enhances operational frequency, and improves power handling capabilities of transistors by reducing parasitic capacitance and thermal stress, leading to more efficient and reliable high-frequency semiconductor devices.
Implementation Method 1
parasitic capacitive coupling between these passive devices and the conductive silicon substrate
Implementation Method 2
A semiconductor structure is developed with a dielectric structure that surrounds and isolates active areas, reducing parasitic capacitance
Implementation Method 3
incorporating a dielectric platform with a low dielectric constant to minimize capacitive coupling and enhance thermal dissipation
Data Source
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AI summary
In various embodiments, semiconductor structures and methods to manufacture these structures are disclosed. In one embodiment, a semiconductor device includes a plurality of rectilinear structures, wherein the plurality of rectilinear structures comprise silicon dioxide and extend from a surface of a semiconductor material to a distance of at least about three microns or greater below the surface of the semiconductor material and wherein a first rectilinear structure of the plurality of rectilinear structures is perpendicular to, or substantially perpendicular to, a second rectilinear structure of the plurality of rectilinear structures. Other embodiments are described and claimed.