Semiconductor Through Electrode Uniformity via Local Substrate Thinning
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Solution Overview
Problem
The existing methods for forming through electrodes in semiconductor devices face challenges due to varying etching rates during reactive ion etching, leading to non-uniform hole diameters and increased defects, which affect electrical resistance and device reliability.
Innovation Solution
A method involving bonding a support substrate to the device substrate, grinding and thinning based on in-plane etching rates, and controlling adhesive thickness to maintain uniform hole diameters, ensuring precise hole formation and reducing defects by managing etching variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the etching rate is reduced to improve hole processing precision and reduce in-plane tendency, then manufacturing precision is improved, but productivity is lowered
Solution Approach 1:
The device substrate is ground and thinned before the RIE process to a thickness that compensates for the in-plane etching rate variation. This preliminary action ensures that even with slower etching rates, the hole bottoms will be at the correct depth, maintaining precision without requiring excessively slow processing speeds
Solution Approach 2:
The substrate thickness is made non-uniform across the wafer surface, with the central region being thinner than the outer peripheral region. This local variation in thickness compensates for the in-plane etching rate differences, allowing uniform hole formation despite regional etching rate variations
2Manufacturing precision
If the device substrate is processed by RIE to form holes, then through electrodes are formed, but the etching rate varies from region to region causing non-uniform hole diameters
Solution Approach 1:
The device substrate is ground to have different thicknesses in different regions: the central region is made thinner while the outer peripheral region is kept thicker. This compensates for the in-plane etching rate variation during RIE, ensuring that holes formed in both central and outer regions achieve uniform diameters and proper depths
Solution Approach 2:
The physical parameter of substrate thickness is changed across different regions of the wafer. By adjusting the thickness parameter before RIE processing, the patent compensates for etching rate variations and achieves uniform hole formation throughout the substrate
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 enables the formation of through electrodes with uniform diameters, reducing defects and improving electrical consistency by aligning with regional etching rates, thus enhancing semiconductor device reliability and productivity.
Implementation Method 1
bonding a first surface of a device substrate on which a device is formed on a first surface to a support substrate via an adhesive
Implementation Method 2
grinding and thinning a second surface side opposite to the first surface of the device substrate
Implementation Method 3
processing the device substrate by RIE (reactive ion etching) to form a hole for forming a through electrode
Data Source
AI summary
According to one embodiment, a method of manufacturing a semiconductor device includes: bonding a first surface of a device substrate on which a device is formed on a first surface to a support substrate via an adhesive; after bonding the device substrate to the support substrate, grinding and thinning a second surface side opposite to the first surface of the device substrate based on an in-plane processing rate at the time of forming a semiconductor substrate by RIE; after thinning the device substrate, forming a hole penetrating the device substrate by RIE; and burying metal in the hole to forma through electrode.