New positive-type photosensitive polyimide having sulfo groups

A new positive-working photosensitive polyimide (PSPI) has been developed, which is based on polyimide bearing sulfo groups (PIS) and 1-{1,1-bis[4-(2-diazo-1-(2H)naphthalenone-5-sulfonyloxy)phenyl]ethyl}-4-{1-[4-(2-diazo-1(2H)naphthalenone-5-sulfonyloxy)phenyl]methylethyl}benzene (S-DNQ) as a photosensitive compound. PIS was prepared by ring-opening polyaddition of 1,3-phenylenediamine-4-sulfonicacid (PDAS), 4,4′-oxydianiline (ODA), and 4,4′-hexafluoropropylidenebis(phthalic anhydride) (6FDA), followed by thermal cyclization in m-cresol. PIS containing 30 wt% of S-DNQ showed a sensitivity of 100 mJ cm⁻² and a contrast of 1.7, when it was exposed to 365 nm light followed by developing with 2.38 wt% aqueous tetramethylammonium hydroxide (TMAH) solution at room temperature. A fine positive image featuring 10 μm line and space patterns was observed on the film of the photoresist exposed to 200 mJ cm⁻² of UV-light at 365 nm by the contact mode. The positive image was successfully converted to the polyimide pattern by thermal treatment.     

Photochemical image enhancement for 0.5 μm g-line lithography

Materials and processing are described that provide 0.5 μm resolution with between 1 and 2 μm total depth of focus using a 436 nm stepper with 0.42 N.A., using the previously described PIE process (SPIE 631, 171 (1986)); 0.4 μm lines, spaces, and line/space gratings were reproduced. The chemistry is based on the photobleaching of anthracene derivatives in the presence of oxygen, followed by a deep-UV pattern transfer exposure under nitrogen. Although resolution and process control are quite good, the exposure time of 1.2 s is somewhat long due to the limited oxygen permeability of the chosen polymer; in addition the strong unbleachable absorbance of the deep-UV resist limits the usable thickness to ～500 nm. Materials have been identified that promise to overcome both limitations, yielding thicknesses of 1 μm or more and exposure times less than 500 ms. Application to 365 and 248 nm imaging is also possible.     

Synthesis and characterization of novel fluorinated polyimides derived from bis[4-(4′-aminophenoxy)phenyl]-3,5-bis(trifluoromethyl)phenyl phosphine oxide

A novel fluorinated aromatic diamine, bis[4-(4′-aminophenoxy)phenyl]-3,5-bis(trifluoromethyl)phenyl phosphine oxide, was synthesized. A series of new fluorinated polyimides containing phosphine oxide was prepared from the novel diamine with various commercially available aromatic dianhydrides. All the fluorinated polyimides show high glass transition temperatures, excellent thermal stability, and good solubility in common organic solvents.     

A negative resist for KrF excimer laser lithography

The design and preparation of a series of negative resists for KrF excimer laser lithography are described. Each resist is composed of poly(hydroxystyrene) and an aromatic azide. The base resin shows high transmittance of 62%/μm at 248 nm, when p-ethylphenyl p-azidophenylsulfonate. 4-azido-4α-methoxy-chalcone, 1-(4 azidobenzylidene)-3-(α-hydroxy-4-azidobenzyl)-indene, 4,4α-diazido-3,3α-dimethoxybiphenyl, or 1-(4-azidostyryl)-5, 5-dimethyl-2-cyclohexen-1-one is employed as a sensitizer. These azides are obtained by red-shifting the absorption maxima to lower energy regions than the exposing wavelength of 248 nm. Transmittance of resists can be controlled from 10 to 30%. The resist is exposed with a KrF excimer laser stepper and developed in an alkaline solution. Sensitivities of about 15 mJ/cm² are observed. A good, subhalf-micron resist profile is achieved. The photochemical reaction mechanisms of poly(hydroxystyrene) and 4,4α-diazido-3,3α-dimethoxybiphenyl were studied at 248 nm and 313 nm exposure. Quantum yield for photodecomposition at 248 nm is seven times larger than that at 313 nm, but dissolution-inhibition effects are larger at 313 nm exposure. Consequently, the resist shows higher sensitivity at 313 nm than at 248 nm.     

Tetrahydropyranyl- and furanyl-protected polyhydroxystyrene in chemical amplification systems

Tetrahydropyranyl- (THP) and furanyl- (THF) protected polyhydroxystyrene (PHS) polymers have been investigated for their potential use in conjunction with onium salt acid precursors to yield high-sensitivity resist systems. The synthesized polymers have high transmittance at 248 nm (the wavelength used in next-generation excimer laser, KrF exposure tools). At 248 nm the transmittance for a 1-μm thick film is ～ 80% (Abs = 0.097 μm^?1). The acid sensitivity of the acetal functionality at room temperature is high, requiring careful handling of all materials to prevent any premature deprotection of the hydroxy group. The highest lithographic sensitivities obtained so far with a system consisting of poly(p-tetrahydropyranyl-oxy-styrene) base resin and 1 mol % of bis (p-tert-butyl phenyl) iodinium triflate (TBIT) was ～ 2 mJ / cm². High-resolution line and space patterns (0.35 μm) were obtained with a system comprising PHS-p-THP and an acid precursor, using an excimer laser step and repeat exposure at 248 nm.     

4-苄基-2-[(R)-1-[3,5-二(三氟甲基)苯基]乙氧基]吗啉-3-酮的不对称转化的动态动力学拆分

以4-苄基-2-羟基吗啉-3-酮为原料,经两步反应制备得到一对非对映异构体4-苄基-2-[(R)-1-[3,5-二(三氟甲基)苯基]乙氧基]吗啉-3-酮,然后以叔丁醇钾为碱环境,利用不对称转化的动态动力学拆分,转化为手性纯(R)-4-苄基-2-[(R)-1-[3,5-二(三氟甲基)苯基]乙氧基]吗啉-3-酮。转化后手性产物与非对映异构体的比例为96∶4,在工业化制备神经激肽-1(NK-1)受体阻滞剂阿瑞吡坦过程中有较好的应用价值。     

A positive‐working photosensitive polyimide based on thermal cross‐linking and acidolytic cleavage

A novel positive‐working photosensitive polyimide (PSPI) based on a poly(hydroxyimide) (PHI), a crosslinking agent having vinyl ether groups, and a photoacid generator (PAG) was prepared. The PHI as a base resin of the three‐component PSPI was synthesized from 4,4′‐oxydiphthalic anhydride and 2,2′‐bis(3‐amino‐4‐hydroxyphenyl)hexafluoropropane through ring‐opening polymerization and subsequent thermal cyclization. 2,2′‐bis(4‐(2‐(vinyloxy)ethoxy)phenyl)propane (BPA‐DEVE) was used as a vinylether compound and diphenyliodonium 5‐hydroxynaphthalene‐1‐sulfonate was used as a PAG. The phenolic hydroxyl groups of the PHI and the vinyl ether groups of BPA‐DEVE are thermally crosslinked with acetal structures during prebake step, and the crosslinked PHI becomes completely insoluble in an aqueous basic solution. Upon exposure to UV light (365 nm) and subsequent postexposure bake (PEB), a strong acid generated from the PAG cleaves the crosslinked structures, and the exposed area is effectively solubilized in the alkaline developer. The dissolution behavior of the PSPI containing each 11.5 wt % of BPA‐DEVE and of the PAG was studied after UV exposure (365 nm) and PEB. It was found that the difference in dissolution rates between exposed and unexposed areas was enough to get high resolution. A fine positive pattern with a resolution of 5 μm in a 3.7‐μm‐thick film was obtained from the three‐component PSPI. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

A novel electrochromic polymer containing triphenylamine derivative and pyrrole

A novel conducting polymer was successfully synthesized via electropolymerization of N¹,N⁴-bis(4-(1H-pyrrol-1-yl)phenyl)-N¹,N⁴-diphenylbenzene-1,4-diamine (DPTPA). This polymer film exhibited six various colors under different potentials. Besides, this polymer film showed high optical contrast (41% at 852 nm, 52% at 617 nm) and fast switching time (1.3 s at 410 nm, 1.4 s at 852 nm and 0.6 s at 617 nm). Cyclic voltammogram and electro-optical study showed that the polymer film has a stable and well-defined reversible redox process as well as electrochromic behavior.     

Optical data storage by novel photoelectrochromic polymer

A novel elastic polymer containing 4,4′-bipyridinium salts with tetrakis[3,5-bis(trifluoromethyl)phenyl]borate as part of the main chain was synthesized. The cast film showed persistent and reversible colour changes due to photoinduced electron transfer upon excitation of an ion-pair charge-transfer band (_ex >365 nm) in vacuo. The lifetime of the coloured state markedly depended on temperature. The optically written data were stored without decay below 0°C and were erased thermally at elevated temperatures. The colour changes were reversibly repeatable for many times.     

Synthesis and memory characteristics of polyimides containing noncoplanar aryl pendant groups

A series of soluble aromatic polyimides were prepared from 2,2′-diphenyl-4,4′-biphenyl diamine (DPBD), 2,2′-bis(biphenyl)-4,4′-biphenyl diamine (BBPBD), 2,2′-bis[4-(naphthalen-1-yl)phenyl]-4,4′-biphenyl diamine (BNPBD) and 2,2′-bis(3,5-dimethoxyphenyl)-4,4′-biphenyl diamine (BMPBD) by polycondensation with 2,2′-bis[4′-(3′′,4′′,5′′-trifluorophenyl)phenyl]-4,4′,5,5′-biphenyl tetracarboxylic dianhydride via a two-step procedure. The resulting polymers were fully characterized and they exhibited excellent organosolubility, high thermal and dimensional stability. Resistive switching devices with the configuration of Al/polymer/ITO were constructed from these polyimides by using conventional solution coating process. Devices with the active layer based on DPBD, BBPBD and BNPBD exhibited nonvolatile and rewritable flash type memory characteristics with the turn-on voltage at ?2.0 to ?3.0 V and the turn-off voltage at 2.0–3.0 V. Whereas, device based on BMPBD demonstrated a bipolar write-once read-many times (WORM) memory capability with the writing voltage around ±3.0 V. The ON/OFF current ratio of these devices was of about 10⁶ and the retention times can be as long as 10⁴ s.     

A sub-0.5 μm bilevel lithographic process using the deep-UV electron-beam resist p(si-cms)

Optimization of the deep-UV and electron-beam lithographic properties of a copolymer of trimethylsilylmethyl methacrylate (SI) and chloromethylstyrene (CMS), P(SI-CMS), within a weight average molecular weight range of 1.4 to 4.1 × 10⁵ and 90 to 93 mole percent SI composition has been achieved. The solubility behavior of P(SI-CMS) resist was examined using the Hansen 3-dimensional solubility parameter model and dissolution rate measurements. Swelling of the resist has been minimized through the identification of a single component developer (2-propanol) and rinse (water) system. For the material containing 90 mole percent SI (14.9 weight percent Si) and M?_ω = 1.4 × 10⁵, the sensitivity to 248 nm radiation is 65 mJ/cm² and to electron-beam exposure is 3.4 μC/cm² at 20 kV. This material Is applicable to bilevel lithographic processes, and the O₂ reactive ion etching (RIE) rate is 16 times slower than standard hard-baked photoresist. Using a He/O₂(60/40) RIE pattern transfer process, 0.4 μm line/space patterns have been resolved in a 1.3 μm bilayer structure for deep-UV exposures, and 0.25 μm imaging has been demonstrated in a 0.7 μm thick planarizing layer using electron beam irradiation. The loss in linewidth associated with the 0.25 μm process is ～0.04 μm.     

Photosensitive poly(benzoxazole) based on precursor from diphenyl isophthalate and bis(o-aminophenol)

A new synthetic method for the preparation of poly(benzoxazole) (PBO) precursor, poly(o-hydroxyamide) (7) from bis(o-aminophenol) (5) and diphenyl isophthalate (6) has been developed. Polymer 7 was prepared by the polycondensation of 5 and 6 in 1-methyl-2-pyrrolidinone (NMP) at 185-205 °C. Model reactions were carried out in detail to elucidate appropriate conditions for the formation of 2-hydroxybenzanilide (3) from o-aminophenol (1) and phenyl benzoate (2). The photosensitive (PBO) precursor based on polymer 7 containing a 22% of benzoxazole unit and 30 wt% 1-{1,1-bis[4-(2-diazo-1-(2H)naphthalenone-5-sulfonyloxy)phenyl]ethyl}-4-{1-[4-(2-diazo-1(2H)naphthalenone-5-sulfonyloxy)phenyl]methylethyl}benzene (S-DNQ) showed a sensitivity of 110 mJ cm⁻² and a contrast of 5.0 when it was exposed to 436 nm light followed by developing with a 2.38 wt% aqueous tetramethylammonium hydroxide solution at room temperature. A fine positive image featuring 8 μm line and space patterns was observed on the film of the photoresist exposed to 200 mJ cm⁻² of UV-light at 436 nm by the contact mode.     

Highly optical transparency and thermally stable polyimides containing pyridine and phenyl pendant

In order to obtain highly optical transparency polyimides, two novel aromatic diamine monomers containing pyridine and kinky structures, 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]diphenylmethane (BAPDBP) and 1,1-bis[4-(5-amino-2-pyridinoxy)phenyl]-1-phenylethane (BAPDAP), were designed and synthesized. Polyimides based on BAPDBP, BAPDAP, 2,2-bis[4-(5-amino-2-pyridinoxy)phenyl]propane (BAPDP) with various commercial dianhydrides were prepared for comparison and structure-property relationships study. The structures of the polyimides were characterized by Fourier transform infrared (FT-IR) spectrometer, wide-angle X-ray diffractograms (XRD) and elemental analysis. Film properties including solubility, optical transparency, water uptake, thermal and mechanical properties were also evaluated. The introduction of pyridine and kinky structure into the backbones that polyimides presented good optical properties with 91–97% transparent at 500 nm and a low cut-off wavelength at 353–398 nm. Moreover, phenyl pendant groups of the polyimides showed high glass transition temperatures (T_g) in the range of 257–281 °C. These results suggest that the incorporating pyridine, kinky and bulky substituents to polymer backbone can improve the optical transparency effectively without sacrificing the thermal properties.     

Oberflächenstrukturierung polymerer Fasern durch UV-Laserbestrahlung, 15. Beschreibung des Temperaturfeldes in PETP-Polymeren während und nach der Laserbestrahlung mit einem gepulsten UV-Laser

For understanding the generation of UV laser induced surface structures of PETP polymers the temperature field within the irradiated surface is calculated in dependence on the laser irradiation wavelength (193 nm, 248 nm, 308 nm), pulse time, pulse form, the irradiation intensity and depth, using temperature-independent material data of PETP polymers known from literature. For this purpose the solution function of the one-dimensional heat differential equation is used. Depending on the order of magnitude of the absorption coefficient of the polymer for UV light of different wavelengths, surface temperatures of approx. 16 000°C (193 nm), 11 000°C (248 nm) and 500°C (308 nm) are calculated at the end of the laser pulse. The temperature input within the polymer layer is limited to only a very small penetration depth. For the irradiation with the two laser wavelengths of 193 nm and 248 nm this is less then 0.4 μm. The cooling process is considerably slower, reaching the initial temperature after approx. 4 μs.     

Arylmethyl sulfones: A new class of photoacid generators

The X-ray and deep UV radiation response is described for resist systems consisting of poly(4-tert-butoxycarbonyloxystyrene-co-sulfur dioxide) PTBSS combined with an arylmethyl sulfone. A 2:1 4-tert-butoxycarbonyloxystyrene (TBS): sulfur dioxide (SO₂) resist has been found to function as a highly sensitive, 1.4 nm X-ray, single-component, chemically amplified resist. The same resist, however, exhibits reduced sensitivity to 0.8 nm X-rays and deep UV (248 nm) radiation. Improvement in 0.8 nm X-ray sensitivity is achieved by the addition of 12 mol% bis(3,4-dichlorobenzyl) sulfone (DCBS) to the 2:1 TBS:SO₂ resist. For this two-component resist formulation, the 0.8 nm X-ray sensitive improved from >375 to 125 mJ/cm². Similarly, the sensitivity of the 3:1 TBS:SO₂ copolymer to deep UV radiation improves to 40 mJ/cm² with addition of 10 mol% DCBS. Sulfones, such as DCBS, provide two-component resist formulations capable of <0.5 μm resolution.     

Highly sensitive self-developing soft X-ray resists of silicon-containing aldehyde copolymers and sensitive novolac-based composite resists containing aldehyde copolymer

Copolymers of aliphatic aldehydes containing a trimethylsilyl group were prepared at ?78°C in toluene using diethylaluminum diphenylamide as an initiator. The copolymer depolymerized into monomeric aldehydes on exposure to soft X-rays. When the copolymer was used as a soft X-ray resist, almost complete development was accomplished by exposure alone. No development step was required. The soft X-ray sensitivity of poly(3-trimethylsilylpropanal-co-propanal) was 50 mJ/cm² at the film thickness of 1.0 μm. A composite resist system consisting of a novolac resin and an aldehyde copolymer containing trimethylsilyl groups has also been developed and used as an alkaline-developable positive electron-beam and soft X-ray resist.     

DABA-BAPP-BPADA共聚聚酰亚胺的合成与性能

用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)及3,5-二氨基苯甲酸(DABA)作为二胺,2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)作为二酐,以N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,分别经热亚胺化和化学亚胺化过程合成了可溶性共聚聚酰亚胺。用FT-IR对聚合物的结构进行了表征,性能测试采用了溶解性测试、DSC、TGA、拉伸测试和吸水率测试。FT-IR图谱表明,在1 780cm~(-1)、1720 cm~(-1)和740 cm~(-1)左右出现了聚酰亚胺的特征吸收峰。共聚聚酰亚胺在常见有机溶剂中可溶,并且有很好的热稳定性,玻璃化转变温度T_g为226.5℃,在氮气氛中降解起始温度508.5℃,800℃质量保持率为46.5%。共聚聚酰亚胺膜的拉伸强度、拉伸模量、断裂伸长率分别为109.7MPa、2.25GPa和15.2%。     

3,5-双(4-氨基苯氧基)苯甲酸的合成及其聚酰亚胺薄膜的性能研究

合成3,5-双(4-氨基苯氧基)苯甲酸(35BAPBA)。其方法为3,5-二羟基苯甲酸(35DHBA)和对氯硝基苯(PCNB)通过缩合反应,合成得到了3,5-双(4-硝基苯氧基)苯甲酸(35BNPBA);然后,进一步还原,得到3,5-双(4-氨基苯氧基)苯甲酸(35BAPBA),基于35BAPBA单体,制得多种结构的含羧基芳香族聚酰亚胺薄膜,并对这些薄膜的性能进行研究。制得的3,5-双(4-氨基苯氧基)苯甲酸(35BAPBA)的熔点为245.8℃,且纯度高。各类薄膜的透过率均可达80%以上,具有良好的紫外吸收性能;吸水性均小于3%,具有优异的疏水性能;其拉伸强度在15~56MPa之间。     

Synthesis and characterization of highly optical transparent and low dielectric constant fluorinated polyimides

Multitrifluoromethyl-substituted aromatic diamines, 1,1-bis[4-(4′- amino-2′-trifluoromethylphenoxy)phenyl]-1-(3″-trifluoromethylphenyl)-2,2,2-trifluoroethane (12FDA) and 1,1-bis[4-(4′-amino-2′-trifluoromethylphenoxy)phenyl]-1-[3″,5″-bis (trifluoromethyl)phenyl]-2,2,2-trifluoroethane (15FDA) were synthesized, which were employed to react with various aromatic dianhydrides to yield a series of highly fluorinated polyimides. The fluorinated polyimides synthesized showed great solubility with inherent viscosities of 0.47-0.69 dL/g. The strong and tough polyimide films exhibited good thermal stability with the glass transition temperature (T_g) of 209-239 °C and outstanding mechanical properties with the tensile strengths of 88-111 MPa and tensile modulus of 2.65-3.17 GPa. Dielectric constants of as low as 2.49 and low moisture absorptions (0.17-0.66%) were measured. The fluorinated polyimide films (7-10 μm in thickness) also showed highly optical transparency with light transmittance at 450 nm of as high as 97.0% and cutoff wavelength of as low as 298 nm. The average refractive indices and birefringence of the fluorinated polyimide films were measured in the range of 1.5060-1.5622 and 0.0036-0.0095, respectively. PI-7 and PI-8 exhibited low light-absorption in the near-infrared region, especially at the optocommunication wavelength of 1310 nm and 1550 nm.     

Solvent penetration and photoresist dissolution: A fluorescence quenching and interferometry study

A novel method, based upon fluorescence quenching measurements, is described for the study of the mechanistic details of solvent penetration into thin polymer films. Here poly(methyl methacrylate) (PMMA) labelled with phenanthrene (Phe) groups was coated as a film (0.8 μm thick) onto quartz disks. Diffusion of solvent (1 : 1 2-butanone/2-propanol) into the film was followed by a decrease in Phe fluorescence, while film dissolution was monitored simultaneously by laser interferometry. In the case of PMMA (M_w = 411,000, films annealed at 160°C) both processes occur at approximately the same rate and exhibit non-Fickian (relaxation-controlled) diffusion behavior. Correlating the results of these two experiments shows that, once the steady state is reached, the dissolution rate is controlled by the advance of the solvent front into the PMMA film. The “transition layer,” an important dissolution parameter, increases its thickness from 50 to 90 nm during the plasticization stage of solvent penetration and maintains its thickness until the solvent front reaches the quartz substrate.