Semiconductor Device Manufacturing via Segmented Hydrogen Sintering
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Solution Overview
Problem
Current methods for manufacturing CMOS image sensors fail to adequately terminate dangling bonds at the silicon-oxide interface at temperatures around 400°C, leading to leakage currents and poor device performance due to insufficient dark-time white spots and dark current reduction.
Innovation Solution
A method involving a semiconductor substrate with a gettering layer formed by ion implanting a cluster, followed by a heat treatment at 800°C or more to create a hydrogen adsorption site, and subsequent heat treatment at 600°C or more to effectively terminate dangling bonds and improve device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrogen sintering is performed at temperatures around 400°C, then the process is compatible with element characteristics and wire heat resistance, but the dangling bonds at the silicon-oxide interface cannot be terminated sufficiently, causing leakage current
Solution Approach 1:
The patent divides the hydrogen sintering process into two distinct stages: a first heat treatment at 400°C or higher to form hydrogen adsorption sites in the gettering layer, and a second heat treatment at 600°C or higher to terminate dangling bonds at the silicon-oxide interface. This segmentation allows each stage to serve its specific function without compromising the other, resolving the contradiction between maintaining element/wire integrity and achieving sufficient dangling bond termination.
Solution Approach 2:
The first heat treatment at 400°C or higher is performed as a preliminary action to form hydrogen adsorption sites in the gettering layer before the second heat treatment. This preliminary formation of hydrogen adsorption sites ensures that sufficient hydrogen is available during the subsequent high-temperature treatment to terminate dangling bonds effectively, while the initial low-temperature step preserves element characteristics and wire heat resistance.
2Manufacturing precision
If the temperature of hydrogen sintering is increased to 600°C or more, then dangling bonds can be effectively terminated, but the element characteristics and wire heat resistance may be compromised
Solution Approach 1:
The patent segments the heat treatment process into two stages with different temperature ranges: the first stage at 400°C or higher preserves element characteristics and wire heat resistance, while the second stage at 600°C or higher effectively terminates dangling bonds. This temporal and functional segmentation resolves the contradiction by applying appropriate temperatures at appropriate times for different objectives.
Solution Approach 2:
The patent changes the temperature parameter in a stepwise manner: first maintaining temperature at 400°C or higher to preserve sensitive components, then increasing to 600°C or higher to achieve effective dangling bond termination. This dynamic parameter adjustment resolves the contradiction between protecting sensitive elements and achieving thorough bond termination.
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 significantly reduces interface levels, improving the electric characteristics and performance of CMOS image sensors by effectively eliminating hydrogen and terminating dangling bonds, thereby enhancing the reduction of dark-time white spots and dark current.
Implementation Method 1
providing a semiconductor substrate having a gettering layer formed by ion implanting a cluster in the inside thereof
Implementation Method 2
subjecting the semiconductor substrate to a heat treatment at 800° C. or more, thereby to form a hydrogen adsorption site
Implementation Method 3
a technology referred to as 'hydrogen sintering)' of terminating the dangling bond by hydrogen
Data Source
AI summary
The performances of a semiconductor device are improved. A method for manufacturing a semiconductor device includes the steps of: providing a semiconductor substrate having a gettering layer formed by ion implanting a cluster, and an epitaxial layer; subjecting the semiconductor substrate to a heat treatment at 800° C. or more, and thereby forming a hydrogen adsorption site; forming an element isolation film at the semiconductor substrate, to be performed thereafter; implanting an impurity for forming a first semiconductor region in the semiconductor substrate; implanting an impurity for forming a second semiconductor region; and performing a heat treatment for a photodiode, to be performed thereafter.