Hydrogenated Silicon Sputtering for CMOS-Compatible Photonics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current silicon photonics technologies face challenges in integrating photonic circuitry with electronic circuitry due to compatibility issues, high temperatures required for deposition, and limited wavelength operation ranges, which restricts the integration with CMOS fabrication flow and results in non-uniform thickness and optical properties.
Innovation Solution
The method involves using reactive magnetron sputtering to deposit hydrogenated semiconductor materials like hydrogenated silicon (Si:H) on a substrate at lower temperatures, enabling the formation of planar waveguides and optical filters with tailored optical properties and higher refractive indices, allowing operation in wider wavelength ranges, including the near-infrared regime, and improving integration with CMOS processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods are used to fabricate photonic circuits, then integration with electronic circuitry is achieved, but high temperatures are required and uniformity is poor
Solution Approach 1:
The patent changes the deposition method from conventional high-temperature techniques to sputtering, which operates at lower temperatures. By adjusting sputtering parameters such as power density, gas pressure, and substrate bias, the process achieves both low temperature operation and improved thickness uniformity across the substrate
Solution Approach 2:
The patent replaces thermal-field-based deposition methods with a momentum-based sputtering process. Instead of relying on thermal energy to deposit materials, the process uses kinetic energy from ion bombardment to eject and redeposit material, eliminating the need for high temperatures while achieving uniform film formation
2Adaptability or versatility
If conventional photonic materials are used, then fabrication is simplified, but wavelength operation range is limited
Solution Approach 1:
The patent employs composite material structures, combining sputtered semiconductor layers with dielectric materials to create photonic devices that operate across multiple wavelength ranges. The semiconductor material provides tunable optical properties while the dielectric layers enable waveguide and resonator structures, achieving broad wavelength adaptability through material composition rather than device complexity
Solution Approach 2:
The patent applies local quality by creating regions with different material compositions and optical properties within the same photonic device. By varying the semiconductor layer thickness, composition, and doping locally, the device can handle different wavelength ranges in different regions, enabling multi-wavelength operation without increasing overall fabrication complexity
3Ease of manufacture
If discrete photonic components are used, then component fabrication is simple, but integration with electronic circuits is difficult
Solution Approach 1:
The patent merges photonic and electronic circuit fabrication into a single integrated process using sputtering. Both photonic waveguides and electronic interconnects can be deposited in the same chamber using the same equipment, eliminating the need for separate fabrication lines and reducing integration complexity while maintaining component fabrication simplicity
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 enables better uniformity, lower deposition temperatures, and enhanced optical properties, facilitating the integration of silicon photonics with CMOS processes, expanding the wavelength window of operation, and reducing costs while improving photoconductivity and doping capabilities.
Implementation Method 1
a method for fabricating a photonic integrated circuit may include: injecting hydrogen and a sputtering gas into a chamber of a sputtering system; and sputtering, based on injecting the hydrogen and the sputtering gas into the chamber, at least one layer of a hydrogenated semiconductor material onto a substrate disposed in the chamber of the sputtering system
Implementation Method 2
The at least one layer of the hydrogenated semiconductor material may be sputtered onto the substrate using reactive magnetron sputtering
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A sputtering system may inject hydrogen and a sputtering gas into a chamber of the sputtering system, which may cause at least one layer of a hydrogenated semiconductor material, such as hydrogenated silicon (Si:H), to be sputtered onto a substrate disposed in the chamber until the at least one layer has a thickness that satisfies a threshold. In some implementations, the hydrogen and the sputtering gas may be injected into the chamber of the sputtering system while a temperature in the chamber is in a range from 145 degrees Celsius to 165 degrees Celsius. Accordingly, in some implementations, the sputtered layer of the hydrogenated semiconductor material may have one or more optical properties that satisfy a threshold to enable operation in a 9xx nanometer wavelength regime and at larger wavelengths.