Hydrogen Passivation for Semiconductor Device Reliability
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Solution Overview
Problem
Silicon dangling bonds at the interface between a silicon substrate and a gate dielectric layer in MOSFET-type semiconductor devices can degrade the reliability of semiconductor devices by altering the threshold voltage, affecting transistor characteristics.
Innovation Solution
A method involving the formation of a hydrogen-containing top electrode in a capacitor, including a silicon germanium layer, and an annealing process in a hydrogen-containing gas atmosphere to passivate silicon dangling bonds, thereby reducing their presence at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional MOSFET structure is used with a gate dielectric layer on silicon substrate, then the device can be manufactured with standard processes, but silicon dangling bonds at the interface cause threshold voltage variation and degrade device reliability
Solution Approach 1:
A hydrogen-containing dielectric layer is introduced as an intermediary between the silicon substrate and the gate dielectric layer. This intermediate layer serves as a hydrogen source that supplies hydrogen atoms to passivate silicon dangling bonds at the interface during subsequent annealing processes, thereby eliminating the harmful interface traps without requiring changes to the fundamental MOSFET structure
Solution Approach 2:
The hydrogen-containing dielectric layer is formed in advance before the gate dielectric layer is deposited. This preliminary action ensures that hydrogen is already positioned at the interface region where silicon dangling bonds will form, enabling effective passivation during subsequent thermal annealing without requiring additional processing steps after gate dielectric formation
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 effectively removes silicon dangling bonds, improving the reliability of semiconductor devices without deteriorating transistors in peripheral circuit regions, enhancing data retention time in DRAM devices by more than 10%.
Implementation Method 1
performing an annealing process for hydrogen passivation after the capacitor is formed
Implementation Method 2
performing an annealing process for hydrogen passivation after the capacitor is formed
Implementation Method 3
performing a plasma doping process for doping the top electrode layer with hydrogen
Data Source
AI summary
A method for fabricating a semiconductor device includes: forming a transistor in a semiconductor substrate; forming a capacitor including a hydrogen-containing top electrode over the transistor; and performing an annealing process for hydrogen passivation after the capacitor is formed.