Deep Trench Ring-Capacitor Layout With Shared Etch and Oxide Steps
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Solution Overview
Problem
Conventional semiconductor deep trench devices require separate process steps for forming deep trench insulator and capacitor devices, necessitating twice the number of photomasks and process steps, which can cause severe loading effects.
Innovation Solution
A combination structure and manufacturing method that simultaneously forms deep trench ring and hole units using vertical etching and oxidation growth processes, followed by polysilicon filling, to create both insulator and capacitor devices, reducing the number of steps and enabling a concentric multilayer arrangement for increased isolation voltage and capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate process steps are used to form deep trench insulator and capacitor devices, then each device can be formed with dedicated process optimization, but the number of photomasks and process steps doubles, causing severe loading effects
Solution Approach 1:
The patent combines the formation of deep trench insulator devices and capacitor devices into a single integrated process. Both device types share common process steps including photomask fabrication, vertical etching to form deep trenches, oxidation growth of dielectric sidewall layers, and polysilicon deposition. This merging reduces the total number of photomasks from two to one and consolidates process steps, thereby improving manufacturing efficiency while maintaining dedicated process optimization through selective treatment steps for each device type.
2Ease of manufacture
If separate process steps are used for deep trench insulator and capacitor devices, then each device structure can be independently optimized, but the manufacturing complexity and loading effects increase significantly
Solution Approach 1:
The patent creates a universal process platform that can form both deep trench insulator devices and capacitor devices using the same sequence of process steps. The photomask, etching, oxidation, and polysilicon deposition processes serve dual purposes for both device types. After the shared process steps, selective treatments are applied: insulator devices receive trench filling with insulating material, while capacitor devices receive additional electrode formation. This universal approach simplifies manufacturing by reducing process duplication while managing complexity through modular selective steps.
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 method reduces manufacturing steps by half, decreases loading effects, and enhances isolation voltage and capacitance per unit area through a concentric multilayer design of deep trench units.
Implementation Method 1
a first dielectric sidewall layer formed and completely covering a bottom and sidewalls inside the deep trench ring by an oxidation growth process step
Implementation Method 2
a deep trench ring formed by a vertical etching process step etching the semiconductor substrate
Implementation Method 3
a first polysilicon fill region formed and filling an internal space of the first dielectric sidewall layer with polysilicon material by a depositing process step
Data Source
AI summary
A combination structure of semiconductor deep trench devices includes: a deep trench insulator device, which includes at least one deep trench ring unit, wherein the deep trench ring unit includes: a deep trench ring, a first dielectric side wall layer and a first poly silicon fill region; and a deep trench capacitor device, which includes a plurality of deep trench capacitor units and a cathode, wherein each of the deep trench capacitor units includes: a deep trench hole; a second dielectric side wall layer; and a second poly silicon fill region. The deep trench hole is formed by etching a semiconductor substrate with a same etch process step with the deep trench ring. The first dielectric side wall layer and the second dielectric side wall layer is formed by a same oxide growth process step.