Schottky Barrier Diode Interface Cleaning for Lower Leakage
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Solution Overview
Problem
Existing Schottky barrier diodes suffer from high leakage current due to insufficient Schottky barrier height at the metal-semiconductor interface, often caused by poor process control and contamination, which degrades device performance and increases manufacturing costs.
Innovation Solution
A method for manufacturing Schottky barrier diodes that involves sharing oxide layers with MOS transistors to improve process integration, using thermal treatments and two-step patterning of dielectric layers to ensure complete removal of residual materials, thereby maintaining forward current and reducing leakage current without additional processing time or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional process integration techniques are used for manufacturing Schottky barrier diodes, then manufacturing cost is reduced, but leakage current increases due to insufficient Schottky barrier height and interface contamination
Solution Approach 1:
The patent combines the oxide layer formation process for Schottky barrier diodes with the gate oxide formation process for MOS transistors into a single unified process step. This merging eliminates the need for separate oxide deposition and cleaning steps, reducing process complexity while ensuring clean metal-semiconductor interfaces that minimize leakage current.
Solution Approach 2:
The oxide layer serves dual functions: it acts as a gate oxide for MOS transistors and simultaneously provides a clean interface layer for Schottky barrier diodes. This multi-functionality allows the same process step to benefit both device types, improving Schottky barrier height without adding manufacturing steps.
2Reliability
If additional processing steps are added to improve Schottky barrier height and reduce leakage current, then device performance improves, but processing time and cost increase
Solution Approach 1:
The oxide layer is formed in advance as part of the standard CMOS process sequence, before the metal deposition step for Schottky barriers. This preliminary action ensures the interface is already prepared and cleaned, eliminating the need for additional interface preparation steps later in the process.
Solution Approach 2:
The thermal processing steps already required for MOS transistor fabrication automatically serve to form and condition the oxide layer at the Schottky barrier interface. The same annealing and cleaning conditions that benefit MOS devices also improve the Schottky interface, making the process self-sufficient without requiring dedicated Schottky processing steps.
3Manufacturing precision
If extensive cleaning and preparation steps are implemented to remove residual materials, then interface quality improves, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the cleaning function from separate dedicated cleaning steps and integrates it into the standard oxide formation process. The oxide deposition and subsequent thermal processing automatically remove organic and inorganic contaminants from the semiconductor surface, eliminating the need for separate cleaning operations.
Solution Approach 2:
The oxide layer acts as an intermediary between the semiconductor substrate and the metal contact. It provides a controlled interface that naturally prevents contamination from direct metal-substrate contact while facilitating good electrical contact, thereby reducing the need for extensive cleaning procedures.
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 proposed method effectively reduces leakage current and maintains forward current performance by ensuring a clean metal-semiconductor interface, improving the overall efficiency and reliability of Schottky barrier diodes.
Implementation Method 1
performing a thermal treatment process to remove a residual material
Data Source
AI summary
A method of manufacturing a Schottky barrier diode includes: forming a first well region and a second well region adjacent to the first well region in a substrate; depositing a first dielectric layer over the first well region and the second well region; performing a first patterning operation on the first dielectric layer to cause the first dielectric layer to include a stepped shape; performing a second patterning operation on the first dielectric layer to form a gate dielectric layer of a first transistor device in the second well region; and forming a conductive layer over the first well region to obtain a Schottky barrier interface.