Embedded Material Gate Proximity Control via Oxide Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices miniaturize, controlling the parameters of embedded silicon-straining materials, such as embedded silicon germanium (eSiGe) structures, becomes increasingly difficult, particularly the proximity of these materials to the gate, which significantly affects device performance and yield.
Innovation Solution
Implementing advanced process control (APC) methods, including feedback and feedforward control, to monitor and adjust the proximity of embedded materials to the gate through inline measurement and process adjustments, ensuring accurate control of the recess formation and nitride spacer etch processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional scaling is used to decrease device dimensions, then device size is reduced, but performance benefits are diminishing
Solution Approach 1:
The patent changes the physical state and material composition parameters by introducing embedded silicon-straining materials (SiGe, SiC) with different lattice constants into the semiconductor structure. This modifies the carrier mobility parameter through strain engineering, allowing performance improvement without further scaling down device dimensions.
Solution Approach 2:
The patent uses composite material structures by embedding silicon-straining materials (SiGe, SiC) within the semiconductor device architecture. These composite structures combine the electrical properties of silicon with the strain-inducing properties of SiGe/SiC, achieving enhanced carrier mobility while maintaining device functionality.
2Reliability
If embedded silicon-straining materials are used to enhance carrier mobility, then device performance is improved, but control of material parameters becomes increasingly difficult
Solution Approach 1:
The patent implements feedback control by measuring the actual proximity of embedded materials to the gate and using this measurement to adjust subsequent processing parameters. This closed-loop control system compensates for variations in material deposition and etching processes, maintaining precise control over the critical proximity parameter despite manufacturing variability.
Solution Approach 2:
The patent applies preliminary action by using feedforward control to pre-adjust processing parameters based on measured values from previous steps. The system measures parameters during recess formation and uses this information to pre-compensate for expected variations in subsequent steps, preventing deviations before they occur.
3Manufacturing precision
If proximity of embedded material to gate is not accurately controlled, then manufacturing variability increases, but implementing advanced process control adds process complexity
Solution Approach 1:
The patent uses feedback control to automatically adjust processing parameters based on real-time measurements of the proximity parameter. This eliminates the need for complex manual intervention and multiple process steps, as the feedback system automatically compensates for variations, actually simplifying the overall control process while improving precision.
Solution Approach 2:
The patent implements self-service through automated measurement and control systems that perform inline monitoring and self-adjustment of processing parameters. The system uses its own measurement data to automatically correct deviations, reducing the need for external intervention and complex process management.
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 allows for precise control of the embedded material/gate proximity, enhancing semiconductor device performance and yield by aligning the innermost edges of the recess with the gate, thereby improving carrier mobility and reducing manufacturing variability.
Implementation Method 1
a proximity value, which is defined as a distance between the gate and a closest edge of the recess, is controlled by controlling formation of an oxide layer provided beneath the gate
Implementation Method 2
Since the lattice constant of SiGe is different from that of silicon, mechanical strain is induced in the crystal layers to accommodate the lattice mismatch
Implementation Method 3
The electrons in such tensile strained silicon layers have greater mobility than in conventional, relaxed silicon layers with smaller inter-atom spacings
Data Source
AI summary
A method that includes forming a gate of a semiconductor device on a substrate and forming a recess for an embedded silicon-straining material in source and drain regions for the gate. In this method, a proximity value, which is defined as a distance between the gate and a closest edge of the recess, is controlled by controlling formation of an oxide layer provided beneath the gate. The method can also include feedforward control of process steps in the formation of the recess based upon values measured during the formation of the recess. The method can also apply feedback control to adjust a subsequent recess formation process performed on a subsequent semiconductor device based on the comparison between a measured proximity value and a target proximity value to decrease a difference between a proximity value of the subsequent semiconductor device and the target proximity value.