Quadrangular Interposer Waveguides for Overlay Shift Reduction
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Solution Overview
Problem
The existing silicon photonics technology faces issues with light propagation loss due to overlay shifts in exposure masks during the manufacturing of silicon waveguides, leading to irregularities on the surface and degradation of optical propagation characteristics, especially when multiple exposure masks are used for large semiconductor chips.
Innovation Solution
A semiconductor device with a quadrangular interposer design where silicon waveguides are formed within a single functional block, eliminating the need for divided exposure and reducing the number of exposure masks required, thereby minimizing overlay shifts and light propagation losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple exposure masks are used for large semiconductor chips, then the chip area can be fully covered, but overlay shifts occur at boundaries causing light propagation loss
Solution Approach 1:
The patent divides the large semiconductor chip into multiple smaller chips, each small enough to be exposed using a single exposure mask. This segmentation eliminates boundary regions where overlay shifts occur, thereby maintaining manufacturing precision while still covering the required total chip area through the interposer that can accommodate multiple smaller chips.
Solution Approach 2:
The patent introduces an interposer as an intermediary component between the chip array and the final packaging. The interposer provides a standardized interface that accommodates multiple smaller chips, enabling them to be connected and configured as a functional system without requiring precise overlay alignment across multiple exposure masks.
2Area of stationary object
If divided exposure is used for large chips, then the chip area can be covered, but small irregularities form on waveguide surface causing light scattering
Solution Approach 1:
By segmenting the large chip into smaller chips that can be exposed using a single mask, the patent eliminates the boundary regions where overlay shifts cause surface irregularities. Each smaller chip's waveguides are formed without irregularities, maintaining reliable optical propagation characteristics while the interposer accommodates multiple such chips.
3Manufacturing precision
If a single exposure mask is used for each functional block, then overlay shifts are eliminated, but the interposer requires a large plane area
Solution Approach 1:
The patent segments the functional requirements into multiple smaller chips, each processable with a single exposure mask. This allows high manufacturing precision to be maintained while the interposer area is optimized by efficiently packing multiple smaller chips, reducing the total area compared to using a single large mask.
4Area of stationary object
If multiple exposure masks are used, then large chip area can be processed, but mask costs increase and processing complexity increases
Solution Approach 1:
The patent segments the chip into smaller units that can be processed with a single exposure mask, thereby reducing the number of masks required and simplifying the exposure process. This segmentation strategy lowers mask costs and reduces processing complexity while still achieving the required total chip area through the interposer.
Data Source
AI summary
An interposer includes a plurality of identical functional blocks arranged in the x direction, for example, and the functional blocks include a first region mounting a semiconductor chip, a second region mounting a light emitting element chip, a third region mounting a light receiving element chip, and a plurality of silicon waveguides. Then, the second and third regions are arranged between the first region and a first side along the x direction of the interposer. In addition, the plurality of silicon waveguides are arranged between the second region and the first side, and between the third region and the first side, extending from the second region toward the first side and from the third region toward the first side and are not formed between the functional blocks adjacent in the x direction.