Semiconductor Device Pad Overlap Reduces Chip Area
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Solution Overview
Problem
The integration of an electrostatic breakdown prevention circuit in semiconductor devices, such as heterojunction bipolar transistors (HBTs) used in RF amplifier modules, leads to an increase in chip area due to the need for multiple diodes connected in series, which occupies significant space.
Innovation Solution
A semiconductor device design that incorporates a protection circuit with a pad conductive layer and protection diodes formed on the substrate, where the pad conductive layer partially overlaps the protection circuit, allowing for a more compact layout by reducing the chip area and facilitating efficient voltage release to ground, while maintaining effective electrostatic discharge protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple diodes are connected in series to form a protection circuit, then electrostatic discharge protection function is improved, but chip area increases
Solution Approach 1:
The pad conductive layer is designed to overlap with the protection circuit in plan view, merging the pad structure with the protection circuit structure. This spatial overlap allows the protection circuit to share the area occupied by the pad conductive layer, thereby reducing the total chip area while maintaining the electrostatic discharge protection function provided by the series-connected diodes
Solution Approach 2:
The invention transitions from a two-dimensional lateral arrangement where the pad and protection circuit are side-by-side to a three-dimensional overlapping arrangement where the pad conductive layer is positioned above the protection circuit. This vertical stacking in the third dimension enables area reduction by utilizing the z-axis space rather than requiring additional lateral space
Data Source
AI summary
An amplifier circuit including a semiconductor element is formed on a substrate. A protection circuit is formed including a plurality of protection diodes that are formed on the substrate and that are connected in series with each other, the protection circuit being connected to an output terminal of the amplifier circuit. A pad conductive layer is formed that at least partially includes a pad for connecting to a circuit outside the substrate. An insulating protective film covers the pad conductive layer. The insulating protective film includes an opening that exposes a partial area of a surface of the pad conductive layer, and that covers another area. A first bump is formed on the pad conductive layer on a bottom surface of the opening, and a second bump at least partially overlaps the protection circuit in plan view and is connected to a ground (GND) potential connected to the amplifier circuit.