Low-temperature void-free wafer-level adhesive bonding for thin film transfer by nano-imprint resist

2012 ◽  
Author(s):  
Fang Zhong ◽  
Tao Dong ◽  
He Yong ◽  
Su Yan
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Adhesive Bonding ◽  
Wafer Level ◽  
Film Transfer ◽  
Nano Imprint

scholarly journals Integration Technology for Wafer-Level LiNbO3 Single-Crystal Thin Film on Silicon by Polyimide Adhesive Bonding and Chemical Mechanical Polishing

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2554
Author(s):  
Wenping Geng ◽  
Xiangyu Yang ◽  
Gang Xue ◽  
Wenhao Xu ◽  
Kaixi Bi ◽  
...  
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Chemical Mechanical Polishing ◽  
Adhesive Bonding ◽  
Mechanical Polishing ◽  
Bonding Interface ◽  
Infrared Analysis ◽  
Mems Devices ◽  
Wafer Level ◽  
Integration Technology

An integration technology for wafer-level LiNbO3 single-crystal thin film on Si has been achieved. The optimized spin-coating speed of PI (polyimide) adhesive is 3500 rad/min. According to Fourier infrared analysis of the chemical state of the film baked under different conditions, a high-quality PI film that can be used for wafer-level bonding is obtained. A high bonding strength of 11.38 MPa is obtained by a tensile machine. The bonding interface is uniform, completed and non-porous. After the PI adhesive bonding process, the LiNbO3 single-crystal was lapped by chemical mechanical polishing. The thickness of the 100 mm diameter LiNbO3 can be decreased from 500 to 10 μm without generating serious cracks. A defect-free and tight bonding interface was confirmed by scanning electron microscopy. X-ray diffraction results show that the prepared LiNbO3 single-crystal thin film has a highly crystalline quality. Heterogeneous integration of LiNbO3 single-crystal thin film on Si is of great significance to the fabrication of MEMS devices for in-situ measurement of space-sensing signals.

Low Temperature Wafer Level Adhesive Bonding Using BCB for Resonant Pressure Sensor

2012 ◽  
Vol 503 ◽  
pp. 55-60 ◽  
Author(s):  
Yu Xin Li ◽  
De Yong Chen ◽  
Jun Bo Wang
Keyword(s):  
Low Temperature ◽  
Pressure Sensor ◽  
Adhesive Bonding ◽  
Time Pressure ◽  
Bonding Process ◽  
Wafer Level ◽  
Bonding System ◽  
Sensor Package ◽  
Bonding Technique

This paper presents a method of low temperature wafer level adhesive bonding using non-photosensitive bisbenzocyclobutene (BCB) from Dow Co for resonant pressure sensor package. The bonding process is performed at the temperature below 250oC, with the pressure on the wafer 2-3 Bar in vacuum in a wafer bonding system. According to the bonding process, pre-bake time, pumping time, pressure placed on the sensor and the thickness of cross-linked layer are the most important factors. Experiments show that more than 95% of the area is successfully bonded, the hermeticity maintains well after thermal shock and long term tests, and the tensile strength of the fabricated bonds is up to 40MPa. The bonding technique was successfully tested in the fabrication process of resonant pressure sensor, and the results show that this bonding technique is a viable MEMS encapsulation technology for hermetically cavity sealing.

Low-temperature thin-film indium bonding for reliable wafer-level hermetic MEMS packaging

2013 ◽  
Vol 23 (7) ◽  
pp. 075007 ◽  
Author(s):  
R Straessle ◽  
Y Pétremand ◽  
D Briand ◽  
M Dadras ◽  
N F de Rooij
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Wafer Level ◽  
Mems Packaging

Laser Direct Patterning of Dry Etch BCB Adhesive Layers for Low Temperature Permanent Wafer-to-Wafer Bonding

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 001222-001254
Author(s):  
Kai Zoschke ◽  
J.-U. Kim ◽  
M. Wegner ◽  
M. Gallagher ◽  
R. Barr ◽  
...  
Keyword(s):  
Low Temperature ◽  
Wafer Bonding ◽  
Adhesive Bonding ◽  
Special Focus ◽  
Transfer Printing ◽  
Wafer Level ◽  
Optical Elements ◽  
Flat Surfaces ◽  
Laser Ablation Process ◽  
Bond Layer

To enable advanced wafer level packaging approaches for devices like MEMS, image sensors or optical elements, wafer-to-wafer bonding processes using structured low temperature curable adhesives are required. A lot of Benzocyclobutene (BCB)-based wafer bonding works have been reported in the past showing a broad range of applications and good performance, but also some limitations such as long bond cycles and high cure temperature of 250 °C. In 2013 new process concepts were demonstrated [1], showing that wafer bond cycle time can be reduced to less than 10 min and a post bond batch cure at temperatures below 200 °C can be used to significantly shrink the overall cost of a BCB-based adhesive wafer bonding process. In order to create a patterned BCB bond layer, photo structuring of CYCLOTENE ® 4000 Resin is one solution. However, due to the decreased flow capability of that material after exposure, high bond forces and extended bonding times during wafer bonding as well as nearly flat surfaces with low topography are required for void-free bonding. To overcome these limitations, an increased material flow capability during wafer bonding is required. In this context non-photo sensitive CYCLOTENE ® 3000 Resin is suitable, since it has excellent flow capability in non-cured state. However, non-cured CYCLOTENE ® 3000 Resin cannot be structured with standard dry etching processes using a photo resist layer as mask. In order to enable patterned adhesive bonding based on CYCLOTENE ® 3000 Resin, alternative structuring methods have to be evaluated. One method was presented in [1] which is transfer printing of CYCLOTENE ® 3000 Resin from a help wafer to topography features of the device wafer. Although very good results were obtained, the method is restricted to applications with significant topography to enable the transfer printing. In this work we focus on a new structuring method for non-cured BCB layers formed from CYCLOTENE ® 3000 Resin. The layers were spin coated, baked and subsequently patterned using a 248 nm excimer laser stepper. The system features a 2.5× mask projection with a resulting exposure field of 6.5 × 6.5 mm2 and allows a direct ablation patterning of polymers. By using this method bond frame structures were patterned into 5 μm thick BCB layers at 200 mm silicon wafers. The wafers with the structured adhesive were bonded at 80 °C and 0.2 MPa for 5 minutes with 200 mm glass wafers. The bonded wafer stacks were subsequently post bond batch cured at 190 °C. Wafer dicing and shear tests of the bonded structures revealed excellent mechanical robustness of the BCB bond frames. The paper will review the new BCB wafer bond processes for supporting short cycle times with special focus on the new patterning approach by laser ablation. Process flow description as well as systematical analysis of pattern reproducibility of the new structuring method is part of the discussion.

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