（中文）
使用高溫起孔洞劑合成介孔洞低介電材料及其孔洞型貌與電性之探討
（英文）
Synthesis, Pore Morphology, and Dielectric Property of Mesoporous Low-k Material PSMSQ Using a Reactive High-Temperature Porogen, TEPSS五、 其他
一、參加經過
本次第 219 屆美國電化學國際研討會 (219th Meeting of the Electrochemical Society) 之秋季會 議於五月一日在加拿大「蒙特婁」盛大舉行，為期六日。在經過了二十幾個小時的飛行之後，學生抵達 位於 Montreal Convention Center 大廳的會場報到，準備參加一連六天的研討會。此次學生之行程為：
四月二十七日晚間十一點二十分由台灣桃園國際機場出發；五月十二日晚上九點三十分點返抵國門。
本會議為世界上最大型的電化學專業領域研討會之ㄧ，舉凡燃料電池、太陽能電池、電化學分析、、單 層石墨應用半導體工業...等，都有非常多的熱門議題被討論，與會人士中不乏各領域產學界之國際知 名專家。而學生的研究成果被安排在星期三 (05/04) 晚間 17:10 至 17:30 的 oral presentation，會 議地點位於 Montreal Convention Center 的 Level 05 511 會議室。本次學生的發表方式為口頭簡 報，過程中必須以英文與詢問者對答，過程緊張，但是事後相當有成就感，並獲得了畢生難忘的經驗。
二、心得（可含照片）
美國電化學國際研討會 (秋季會議) 為每年都會舉辦的大型科技會議之一，參加人數及論文數皆相當眾 多，學術界與業界亦相當看重這個研討會，與會中很多論文議題內容相當充實，因此與其他參加者討論，
都有相當收穫。因為報名人數眾多，為了避免有遺珠之憾，除了口頭成果報告之外，主辦大會還張貼各 研究單位之研究成果海報，讓學生得以掌握國際上最新的研究動態。
圖片為會議中心一景。 圖片為與他校老師討論研究內容並交換心得。
圖片為此次會議所應邀的演講者。 圖片為大家聽演講的狀況。
此次學生所參加的場次為 E7 - Silicon Nitride, Silicon Dioxide, and Emerging Dielectrics，本 場次有許多有關於新型低介電材料、、高介電材料、3D 內連接方式設計與可靠度的研究被發表，國際 上各研究團隊更帶來許多精采的演講內容，令我大開眼界。另外，與會許多的專家學者對於學生所報告 的題目給予了多寶貴的意見，讓學生獲益良多。
研究報告
a. Process challenges for integration of copper interconnects with Low-k dielectric Abst. # 1405
可用 air gap 取代 low-k 材料，但仍有須考量的地方。
b. Pattern with amorphous carbon thin films Abst. # 1406
Film density can be impacted by
1. high temperature deposition (>500oC) 2. ion bombardment during deposition
c. Ultra low dielectric constant materials for 22 nm technology node and beyond Abst. # 1407
1. k < 2.0 需使用 air gap
2. Light with wavelength > 200 nm is needed to preserve Si-CH3 bonds.
3. Adjusting concentration avoid skeleton damage.
d. Development of porosimetry techniques for the characterization of plasma-treated porous ultra low-k materials
Abst. # 1408
1. Challenges of low-k: CMP, clean, sealing 2. 此研究提出使用 ＥＰ 可側 porosity
3. 此研究並利用ＳＰ 可測得 reflection index, pore size, and pore size distribution.
e. A new flexible quantum dot solar cell: heterostructural TiO2 Mesh-TiO2 nanoparticles photosensitized with CdS
Abst. # 106
1. SILAR process can be used for the formation of CdS nanocrystals on T_NT.
2. The addition of an intermediate TiO2 layer through TiCl4 treatment leads to increase in the deposition of CdS
3. The photoelectrochemical responses follow the order: T_NT/T_NP/CdS > T_NT/ CdS
> T_NT
f. In situ grown and deposition of quantum dots onto Titania nanotubes via solvothermal method.
Abst. # 106
1. A solvothermal-based synthesis approach for deposition of high quality thick CdSe nanocrysral coating on T_NT has been demonstrated.
2. Exchanging myristate with thiolacetic acid followed by annealing in an inert atmosphere is highly beneficial.
3. The films demonstrate photoelectrochemical responses.
三、建議
很榮幸能有這個機會出國參加會議，站上國際會議的舞台發表自己的研究成果。當看見有人對自己的成 果有興趣，或是和其他優秀學者互相討論，那種成就感真是難以言喻。也對於能夠了解全世界正在所在 發展技術感到吃驚，認知到自己也該加緊腳步
而此次出國開會期間，其實最大的感受就是在於經費上的不足，補助款項（四萬多）僅可應付機票與部 份報名費用，剩下報名費用及當地食宿實在無法應付。此趟旅程反而讓學生在經濟上有更大的負擔，希 望國家能多補助這種相關會議的名額與金額，或是積極爭取頂尖會議於台灣舉辦，培養國內更多的優秀 人才。
四、攜回資料名稱及內容
1. 本次會議行程 (Meeting Program) 2. 論文發表時間表與論文摘要
3. 本次會議資料 (隨身碟) 4. ECS 當期 Interface 雜誌
五、其他 無
Synthesis, pore morphology, and dielectric property of mesoporous low-k material PSMSQ using a reactive
high-temperature porogen, TEPSS
S.Y. Chiu, H.L. Hsu, M.L. Che, and J. Leu* Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
*1001 University Road, Hsinchu, Taiwan 30049 Tel: +886-3-5131420, Fax: +886-3-5724727,
E-mail: [email protected]
For porous low-k materials using a templating porogen, one of the challenges is the tendency of porogens to aggregate, leading to large pore size/distribution and exacerbated aggregation at higher porosity. Although reactive porogen is effective to limit porogen aggregation and reduce pore size [1], little work explores the reactive high-temperature porogen for the late-porogen removal integration scheme. In this study, a reactive high-temperature porogen, triethoxy-(polystyrene)silane (TEPSS) was synthesized by atom transfer radical polymerization (ATRP) [2] to obtain tight molecular weight (MW) distribution, then grafted onto the poly(methyl-silsesquioxane) (MSQ) matrix to circumvent the phase separation between matrix and porogen in the conventional hybrid approach. Upon the removal of polystyrene by thermal decomposition, uniformly distributed, spherical pores have been successfully achieved for mesoporous low-k MSQ films without porogen aggregation at high porosity up to 40% (k=2.37).
An extremely low polydispersity (1.06-1.12) of TEPSS was obtained by ATRP of styrene monomers with initiator, 3-chloropropyl(triethoxy)silane (CPTES) at 80
oC for 12 hours, while MSQ precursor was obtained by sol-gel reaction of methyltrimethoxysilane (MTMS) in HPF6 as schematically illustrated in Figs. 1(a) and (b).
The high-temperature porogens, TEPSS at different loadings were then grafted onto MSQ matrix through sol-gel reaction at 50 oC to yield porogen-grafted MSQ (PSMSQ) as shown in Fig. 1(c). The MW of TEPSS was investigated as a function of reaction solvents and the amount of initiator. Among three different solvents, molecular weight of TEPSS was 82,000 g/mole (dimethylformamide, DMF), 28,000 g/mole (toluene), and 26,000 g/mole (p-xylene), respectively. A lowest MW in p-xylene resulting from fast polymerization rate was due to the best match of solubility parameters between p-xylene (7.0) with CPTES (7.44) [3]. Meanwhile, high initiator content would also yield lower polymer molecular weight. The molecular weight was reduced from 26,000 g/mole to 3,500 g/mole when the ratio of CPTES/styrene was increased from 1/500 to 1/125. This could be attributed to the increased free radicals in the polymerization process with higher initiator content, leading to lower polymer MW [4]. The TEPSS with the lowest (Mw: 3,500 g/mole) in this study was obtained by using p-xylene at higher initiator concentration. The chemical structures and thermal properties of TEPSS porogen and PSMSQ low-k materials have been validated and examined by 1H-NMR, 29Si-NMR, FTIR, and TGA, which will be described in the full paper.
The porosity, pore morphology, and dielectric properties of PSMSQ porous low-k films using TEPSS (Mw: 3,500 g/mole) were then characterized by XRR, SEM, and C-V dot measurement. Porosity was found to increase from 16% to 54% while the dielectric constant was reduced from 2.66 to 2.18, when the porogen loading
was increased from 0.4 to 43 wt%. The pore morphology of porous low-k MSQ films at various porosities are shown by SEM viewgraphs in Fig. 2: (a) 16%, (b) 27%, (c) 40%, and (d) 54%, respectively. At porosity ≤40%, the pores in the mesoporous films were found to be spherical and uniformly distributed. In addition, their pore size remained around 30 nm, indicating that little porogen aggregation occurred at porosity ≤40%. The obvious aggregation at porosity >40% will be further investigated and discussed.
Overall, this study introduced a novel method for preparing mesoporous materials, PSMSQ by using a reactive high-temperature porogen, TEPSS, suitable for the late-porogen removal integration scheme. In addition, the extremely low polydispersity by using ATRP and controllable reactivity of high-temperature porogen, TEPSS onto MSQ matrix yielded uniformly distributed and spherical pores (~30 nm) without aggregation at high porosity up to 40%.
Fig. 1 Reaction schemes for (a) the high-temperature porogen, TEPSS, (b) MSQ matrix, and (c) porogen-grafted MSQ, PSMSQ
Fig. 2 SEM viewgraphs of porous low-k MSQ films at various porosities: (a) 16%, (b) 27%, (c) 40%, and (d)
[2] J. F. Lutz and K. Matyjaszewski, Macromol. Chem.
Phys., 203, 1385 (2002)
[3] H. Chen, C. Wang, D. Liu, Y. Song, R. Qu, C. Sun, and C. Ji, J Polym Sci Part A: Polym Chem, 48, 128 (2010)
[4] K. Matyjaszewski, J. L. Wang, T. Grimaud, and D. A.
Shipp, Macromolecules, 31, 1527 (1998)