Metal Removal Efficiency in High Aspect Ratio Structures

2016 ◽  
Vol 255 ◽  
pp. 313-318 ◽  
Author(s):  
Philippe Garnier ◽  
Hervé Fontaine
Keyword(s):  
Aspect Ratio ◽  
Removal Efficiency ◽  
High Aspect Ratio ◽  
Metal Contamination ◽  
Metal Removal ◽  
Image Sensors ◽  
Flat Surfaces ◽  
Past Work ◽  
Patterned Wafers ◽  
Cmos Image Sensors

An extremely low level of metal contamination is required for specific devices like memories and CMOS Image sensors. Most of past work in the literature has focused on blanket wafer decontamination, since metrology is mostly adapted to flat surfaces. Metal removal efficiency has been compared between blanket wafers versus high aspect ratio deep trenches wafers. Two different metrology technics enable a quantitative and spatial metal removal determination on patterned wafers. Efficient cleaning in high aspect ratio structures requires much longer cleaning recipes than on flat surfaces.

Metal Removal Efficiency in Deep Submicron Trenches by Wet Chemicals

2014 ◽  
Vol 219 ◽  
pp. 32-35
Author(s):  
Philippe Garnier ◽  
Nathalie Drogue ◽  
Romain Duru
Keyword(s):  
Integrated Circuits ◽  
Removal Efficiency ◽  
Metal Contamination ◽  
Metal Removal ◽  
Deep Submicron ◽  
Metals Removal ◽  
Silicon Trenches

Metal contamination impact on transistors’ degradation has been widely studied. Nonetheless, most of the work has been performed on blanket wafers, or based on punctual yield crisis during the integrated circuits’ manufacturing. This paper proposes a comparison of the contamination and metals removal efficiency between blanket wafers and inside deep silicon trenches.

Rinsing of High-Aspect-Ratio Features on Patterned Wafers

2017 ◽  
Vol 30 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Chieh-Chun Chiang ◽  
Jivaan Kishore ◽  
Srini Raghavan ◽  
Farhang Shadman
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Patterned Wafers

Formulation and Evaluation of Diluted Sulfuric-Peroxide-HF (DSP+) Mixtures for Cleaning High-Aspect Ratio Contacts in 3D NAND

2021 ◽  
Vol 314 ◽  
pp. 161-166
Author(s):  
Kook Hyun An ◽  
Dong Gyu Kim ◽  
Hyun Tae Kim ◽  
Nagendra Prasad Yerriboina ◽  
Tae Gon Kim ◽  
...  
Keyword(s):  
Contact Angle ◽  
Aspect Ratio ◽  
Removal Efficiency ◽  
High Aspect Ratio ◽  
Silica Particles ◽  
Particle Removal ◽  
Predominant Factor

In this study, organic strip, particle removal efficiency and wettability were investigated at different mixing concentrations of diluted Sulfuric-Peroxide-HF (DSP+) solutions with and without the addition of IPA. Organic strip evaluation was carried out with KrF photoresist (PR), and the strip rate was increased rapidly with the increase in H2SO4 concentration mixed with DI water (DIW). The effects of H2O2 and IPA addition on diluted H2SO4 were observed below 30 vol% of H2SO4. The thickness of PR was increased with the addition of H2O2 to the solutions and the strip rate was increased when IPA was added. Silica particles were used to evaluate particle removal efficiency. The concentration of HF was the predominant factor of increasing PRE, and the addition of H2SO4 and H2O2 assisted in obtaining high PRE, while IPA addition reduced PRE. Decreasing of contact angle was observed with an increase of IPA addition to DSP+ solutions, and improved wettability of DSP+ solutions was expected to effectively clean particles in high-aspect-ratio (HAR) contact holes.

scholarly journals Front-Inner Lens for High Sensitivity of CMOS Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1536 ◽  
Author(s):  
Godeun Seok ◽  
Yunkyung Kim
Keyword(s):  
High Resolution ◽  
Aspect Ratio ◽  
High Sensitivity ◽  
Image Sensor ◽  
Image Sensors ◽  
Optical Simulation ◽  
Optical Performance ◽  
Pixel Size ◽  
Cmos Image Sensors ◽  
Pixel Pitch

Due to the continuing improvements in camera technology, a high-resolution CMOS image sensor is required. However, a high-resolution camera requires that the pixel pitch is smaller than 1.0 μm in the limited sensor area. Accordingly, the optical performance of the pixel deteriorates with the aspect ratio. If the pixel depth is shallow, the aspect ratio is enhanced. Also, optical performance can improve if the sensitivity in the long wavelengths is guaranteed. In this current work, we propose a front-inner lens structure that enhances the sensitivity to the small pixel size and the shallow pixel depth. The front-inner lens was located on the front side of the backside illuminated pixel for enhancement of the absorption. The proposed structures in the 1.0 μm pixel pitch were investigated with 3D optical simulation. The pixel depths were 3.0, 2.0, and 1.0 μm. The materials of the front-inner lens were varied, including air and magnesium fluoride (MgF2). For analysis of the sensitivity enhancement, we compared the typical pixel with the suggested pixel and confirmed that the absorption rate of the suggested pixel was improved by a maximum of 7.27%, 10.47%, and 29.28% for 3.0, 2.0, and 1.0 μm pixel depths, respectively.

Specification of Trace Metal Contamination for Image Sensors

2016 ◽  
Vol 255 ◽  
pp. 309-312 ◽  
Author(s):  
Paul W. Mertens ◽  
Simone Lavizzari ◽  
Stefano Guerrieri
Keyword(s):  
Trace Metal ◽  
Dark Current ◽  
Background Noise ◽  
Metal Contamination ◽  
Image Sensors ◽  
Trace Metal Contamination ◽  
Metal Impurities ◽  
Current Contribution ◽  
Cmos Image Sensors ◽  
Internal Generation

CMOS image sensors can suffer from background noise in absence of any light. In order to suppress this it is important to keep this noise, referred to as dark-current low. This implies that the internal generation current should be very low. Trace metal impurities have been reported to increase the generation current. In this study the trap-assisted generation current contributions due to 7 different metal impurities have been calculated. It was concluded that Cu and Mn impurities yield the highest generation current contribution.

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