Vertical Transistor and MGD Trench Layout for Easier Lithography
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Solution Overview
Problem
The integration of a MOS gated diode (MGD) alongside a vertical transistor device in a semiconductor die poses challenges in lithography and manufacturing due to the decreasing distance between gate trenches, increasing the effort required for manufacturing when arranged in a specific lateral direction.
Innovation Solution
The MGD is integrated consecutively with the transistor device in the same longitudinal direction as the gate trench, allowing for a common straight line alignment and shared trench structure, which simplifies lithography and manufacturing by reducing the need for complex alignment and overlapping lithography steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the MGD is arranged aside the transistor device in the second lateral direction (perpendicular to gate trench extension), then the integration density is improved, but the lithography complexity and manufacturing effort increase significantly
Solution Approach 1:
The patent changes the arrangement dimension from the transverse direction (perpendicular to gate trench) to the longitudinal direction (parallel to gate trench extension). This dimensional shift allows the MGD to be positioned along the length of the gate trench rather than across its width, reducing the minimum lateral spacing requirement and simplifying lithography alignment while maintaining integration density.
Solution Approach 2:
The gate trench structure is segmented into multiple functional zones: the transistor device occupies one portion of the trench, while the MGD occupies another portion along the same trench. This segmentation allows both devices to share the vertical trench structure while being distinguished along the longitudinal axis, reducing lithography complexity compared to placing them side-by-side in the transverse direction.
2Area of moving object
If the distance between gate trenches is decreased to increase device density, then the integration density is improved, but the manufacturing precision requirements become more stringent
Solution Approach 1:
The patent merges the gate trench structures of the transistor device and MGD into a single shared trench. Instead of requiring two separate trenches with precise spacing, both devices utilize the same vertical trench, eliminating the need for precise lateral spacing control between trenches and reducing manufacturing precision requirements while maintaining high device density.
Solution Approach 2:
The single gate trench serves multiple functions: it provides the gate structure for the transistor device in one portion and the gate structure for the MGD in another portion. This multi-functional use of the trench structure eliminates the need for multiple precisely-spaced trenches, thereby reducing lithography precision requirements while achieving high integration density.
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 reduces the manufacturing complexity and effort by allowing for a more straightforward integration of MGD and transistor devices, improving the overall efficiency and reducing the criticality of lithography requirements.
Implementation Method 1
The gate region of the transistor device can comprise the gate electrode and for instance a gate dielectric which capacitively couples the gate electrode to the channel region.
Data Source
AI summary
The disclosure relates to a semiconductor die that includes a vertical transistor device having a gate electrode in a gate trench, and a MOS gated diode (MGD) having an MGD gate electrode in an MGD trench. The gate trench of the vertical transistor device has an elongated extension in a first lateral direction. The vertical transistor device and the MGD are arranged consecutively in the first lateral direction.