Sloping Semiconductor Contact Pad for Area Reduction
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Solution Overview
Problem
The challenge lies in forming semiconductor structures under small signal pads on semiconductor substrates without causing operational instability due to voltage fluctuations and in minimizing pad size to enhance the effective area for semiconductor device functionality, while also preventing damage to protective films during wire cutting.
Innovation Solution
A semiconductor device with a pad having a sloping surface is developed, allowing for reduced pad length projection onto the substrate, which enlarges the effective area for semiconductor structure formation and minimizes interference during wire cutting, achieved by forming a sloping oxide film between the pad and the substrate using varying ion injection densities for oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the small signal pad is enlarged to ensure stable operation and prevent voltage fluctuations, then the reliability of the semiconductor device is improved, but the effective area for forming semiconductor structures decreases
Solution Approach 1:
The pad surface is transformed from a flat two-dimensional plane to a three-dimensional sloping surface. By creating a slope on the pad surface, the projected area on the substrate is reduced while maintaining sufficient bonding area for wire connection, thus enlarging the effective area for semiconductor structure formation without compromising reliability
Solution Approach 2:
The physical parameters of the pad surface are changed by introducing a slope angle. This parameter modification allows the pad to occupy less substrate area while maintaining its functional properties for wire bonding and electrical connection, resolving the contradiction between reliability and effective area
2Productivity
If the pad size is reduced to enlarge the effective area, then the productivity of semiconductor device manufacturing is improved, but the reliability of wire bonding and operational stability deteriorates
Solution Approach 1:
By transitioning from a flat pad surface to a sloping surface, the invention reduces the projected pad area on the substrate, thereby enlarging the effective manufacturing area and improving productivity, while the sloped geometry maintains adequate bonding surface area for reliable wire connection
3Ease of operation
If the pad area is reduced to minimize interference during wire cutting, then the ease of operation is improved, but the ability to prevent damage to protective film deteriorates
Solution Approach 1:
The sloping pad surface creates a height difference between the pad surface and the substrate plane. This three-dimensional configuration allows the wire to be pulled and cut over the sloped surface, directing the drag mark formation away from the flat substrate surface and protecting the protective film from damage
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 stabilizes wire bonding by reducing height differences between connecting points, improves electrical properties by enlarging the active region, and prevents damage to protective films by eliminating the need for a drag mark forming region on the pad.
Implementation Method 1
forming a sloping oxide film between the pad and the substrate using varying ion injection densities for oxidation
Data Source
AI summary
A technique for expanding an effective area in which a semiconductor structure required for a semiconductor device to function is desired. With the semiconductor device 2 of this invention, a pad 12 to be connected with a conductive wire 14 is sloping with respect to the surface of the semiconductor device 2 around the pad 12 and along a longitudinal direction of the conductive wire 14. Consequently, the length of the pad 12, when projecting the pad 12 onto the surface of the semiconductor device 2, can be shortened. As a result, the area of the pad region 10 can be reduced and the effective area for forming a semiconductor structure can be enlarged.