Through-Substrate Electrode Structure Without Plasma Etch Damage
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Solution Overview
Problem
Conventional semiconductor devices using the via-last method for forming via holes suffer damage due to dry etching, which can lead to dielectric breakdown and device deterioration, complicating the device configuration with the need for protection diodes.
Innovation Solution
A semiconductor device and manufacturing method featuring a cylindrical insulating film penetrating the semiconductor substrate, with a front surface pad and conductor layer arranged after removing the semiconductor substrate inside the insulating film using methods other than plasma etching, such as wet etching or chemical dry etching, to prevent damage during via hole formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry etching is used to form via holes in the via-last method, then via holes can be formed after diffusion layer and wiring region are formed, but semiconductor elements are damaged due to dielectric breakdown from charging
Solution Approach 1:
A cylindrical insulating film is introduced as an intermediary structure between the semiconductor substrate and the via hole. This insulating film serves as a mediator that prevents direct plasma contact with the semiconductor substrate, thereby blocking the harmful charging effect while still allowing the via hole to be formed through the insulating film using dry etching.
Solution Approach 2:
The cylindrical insulating film is formed in advance before the via hole formation process. This preliminary structure acts as a protective barrier that prevents the harmful effects of dry etching plasma from reaching the semiconductor substrate, thus preventing dielectric breakdown before it can occur.
2Reliability
If protection diodes are added to prevent damage from dry etching, then semiconductor element integrity is maintained, but device configuration becomes complicated
Solution Approach 1:
Instead of adding protection diodes that would complicate the device configuration, a cylindrical insulating film is used as a simpler intermediary structure. This insulating film provides the necessary protection against plasma damage without requiring additional active components or complex circuitry.
Solution Approach 2:
The cylindrical insulating film serves as a disposable protective structure that is formed temporarily during manufacturing to prevent damage, then removed after serving its protective function. This approach is simpler and less costly than adding permanent protection diodes to the device configuration.
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 prevents damage to semiconductor devices during via hole formation by eliminating the need for dry etching, simplifying the manufacturing process and reducing the risk of device deterioration.
Implementation Method 1
performing thermal oxidation to arrange an insulating film on a front surface of the semiconductor substrate including the groove portion
Implementation Method 2
the semiconductor substrate is ground from the back surface side to expose an end portion on a back surface side of the annular insulating film
Implementation Method 3
the semiconductor substrate inside the annular groove portion is removed by etching
Implementation Method 4
etching of a semiconductor or an insulating film is performed by a plasma-like etching gas
Data Source
AI summary
Provided is a semiconductor device that includes a cylindrical insulating film, a front surface side pad, a conductor layer, and a back surface side pad. The cylindrical insulating film is configured in a cylindrical shape penetrating a semiconductor substrate. The front surface side pad is formed adjacent to a front surface of the semiconductor substrate inside the cylindrical insulating film. The conductor layer is arranged adjacent to the front surface side pad and an inner side of the cylindrical insulating film after removing the semiconductor substrate inside the cylindrical insulating film adjacent to the front surface side pad. The back surface side pad is arranged on a back surface of the semiconductor substrate and is connected to the front surface side pad via the conductor layer.