Browsing by Author "Hsieh, Yen-Hui"

Now showing 1 - 4 of 4

Adhesion Property Between Cu, Ti Metal and SU-8, AZ 4620 Polymer Dielectric
(2016-07)
Huang, Yen-Jun
;
Hsieh, Yen-Hui
;
Shih, Jian-Yu
;
Chen, Han-Chun
;
Leu, Jihperng
This study examines the metal/polymer interfacial adhesion strength for Cu, Ti and three polymers, BCB, SU-8 and AZ 4620. Detailed discussion and explanation focused on adhesion mechanism between metal and BCB, AZ 4620 dielectric are provided. The adhesion strengths of metal on polymer layer are measured by four point bending (FPB) test, which showed that copper and titanium have different characteristics in metal-polymer adhesion. Additionally, to figure out the interfacial adhesion mechanisms, X-ray photoelectron spectroscopy (XPS) technique is used to investigate the chemical bonding compositions between interfaces. The results indicate that the adhesion strength is enhanced by the intense reaction between metal and oxygen on the polymer main chain at the metal-polymer interfaces. On the other hand, interfacial adhesion strength is weaken owing to the destruction of polymer structure, thus the bonding between metal and polymer-main-chain debonded oxygen are of no effect on adhesion.
Exploring the Correspondence Between Chemical States and Adhesion Property for Cr, Co Metal/AZ 4620, BCB Polymer Interface
(2018-02-01)
Hsieh, Yen-Hui
;
Huang, Yen-Jun
;
Shih, Jian-Yu
;
Leu, Jihperng
;
Chen, Kuan-Neng
A method is built for describing the relationship between adhesion strength and chemical states of Co/polymer and Cr/polymer interfaces. Based on the chemical bonding model, the adhesion strength is confirmed to be dominated by the metal organic complex at the interfaces. For Cr/polymers interfaces, the formation of metal-organic complex is restricted by the oxidation of metal atoms during deposition, which leads to almost no variation in adhesion from low [benzocyclobutene(BCB)] to high (AZ 4620) oxygenated polymers. On the other hand, a strong adhesion is observed at the Co/BCB interface that arises from the metal-organic bonds associated with hydroxyl groups in the polymer. The method is expected to provide clear analysis to other metal-polymer interfaces for seeking proper combination in heterogeneous integration.
Generating High-Order Transverse Patterns in Optically Pumped Semiconductor Lasers
(2019-11-01)
Tuan, Pi-Hui
;
Hsieh, Yen-Hui
;
Tu, Chin-Wei
;
Lee, Chi-Chun
;
Tsou, Chia-Han
High-order pattern formation in an optically pumped semiconductor laser (OPSL) under a selective pumping with varying spatial overlap between the pump beam and transverse modes is explored. In contrast to transverse pattern generation by off-axis pumped solid-state lasers where the mode order can be flexibly increased, experimental results reveal that the selective pumping fails to realize high-order mode operation in OPSLs when the pump-to-mode size ratio and pump power are insufficiently large. On the other hand, several high-order patterns belonging to the Hermite-Laguerre-Gaussian (HLG) modes are observed when scanning a large-ratio pump beam to specific positions on the gain chip. These HLG modes are experimentally confirmed to mainly originate from the transverse non-uniformity of present OPSL chip, while their structural features cannot be simply correlated with the pump scanning positions. Nevertheless, it is believed that the first-time observation of pure HLG modes under the large-ratio pumping can offer useful insights into the high-order pattern manipulation in OPSLs.
Generation of High-Energy Geometric Structured Beams by Off-Axis Pumped Nd:YAG/Cr4+:YAG Lasers with Degenerate Resonators
(2018-01-01)
Tuan, Pi-Hui
;
Hsieh, Yen-Hui
;
Liang, Hsin-Chih
;
Su, Kuan-Wei
;
Chen, Yung-Fu
Off-axis pumped Nd:YAG/Cr4+:YAG lasers under degenerate cavity conditions are explored to achieve high-pulse-energy geometric modes for beam transformation. The employment of Nd:YAG crystal promises efficient passively Q-switched (PQS) operation with a flexible cavity length to ensure various PQS geometric modes with stable structures can be generated. It is experimentally confirmed that the output energy and peak power of the PQS geometric modes can easily reach up to over 100 mu J and 10 kW with fairly stable pulse trains in pure linear polarization. Various high-energy vortex beams carrying large angular momentum and diverse phase structures are achieved by converting the planar geometric modes into the circular ones to offer promising light sources for potential applications.