摘要:

AbstractA method is described to modify profiles of resist patterns in novolac and diazo‐oxide containing systems. After patterning of the resist, two successive uniform flood exposures are given, one with deep UV (254 nm) at water‐free conditions and the next with near UV (λ>300 nm) at normal atmospheric conditions. The profile which results after development is vertical, concave or overhanging depending on flood exposure conditions and development processing. As the method includes a flood near UV exposure at atmospheric conditions the imagewise exposure energy can be reduced to approximately 35 percent of the normal value. Furthermore it gives also the possibility of using the resist as a deep UV resist. Another important implication is that standing wave effects are completely elimin

ISSN:0032-3888    

DOI:10.1002/pen.760231702

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThin polymer films were irradiated in a high vacuum environment with energetic (∼2MeV) ions. The emitted molecular species were studied with a quadrupole mass spectrometer during bombardment. The emitted species are predominantly small molecules. The efficiency of emission depends strongly upon the electronic energy loss of the incident ions in the film and, hence, upon the velocity and atomic number of the incident ion. The emission efficiency of all species decreases with increasing damage in the film. By pulsing the ion beam, the time dependence of irradiation induced emission of molecular species from the films has been studied. Emission delays of hundreds of milliseconds are observed in some cases. These delays are found to depend upon the emitted species as well as the host film and seem to be associated with diffusion of the species in the film

ISSN:0032-3888    

DOI:10.1002/pen.760231703

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractPoly(4‐vinylphenol) sensitized by an aromatic monoazide compound (4‐azidochalcone), called MRL (MicroResist forLonger wavelengths), has been prepared and evaluated as a negative UV resist. The resist is sensitive to radiation in the 300 to 400 nm region. The sensitivity of MRL is comparable to that of a positive quinonediazide photoresist under exposure to unfiltered light from a high pressure Hg lamp. An aqueous base developer removes the unexposed areas of MRL with no evidence of swelling of the exposed areas, indicating its high resolution capability. The main products in the exposure of MRL films are found to be primary and secondary amines. It is concluded that the formation of secondary amines attached to the polymer chain is responsible for the insolubilization of the exposed MRL in the base develo

ISSN:0032-3888    

DOI:10.1002/pen.760231704

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractSubmicron lines in negative working, substituted polystyrene resists by focused‐ion‐beam lithography were demonstrated. These features were transferred into an underlying molybdenum layer by plasma etching using the resist as an etch mask, with the minimum continuous line having a width of 0.20

ISSN:0032-3888    

DOI:10.1002/pen.760231705

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper will describe a new concept for the production of high contrast photopatterns. The method is designed to produce good quality patterns with very low contrast illumination through the use of photobleachable materials in conjunction with standard photoresists. A very thin bleachable layer is first applied to the photoresist surface. Following conventional exposure, the layer is removed and the resist developed in the ordinary way. As a result of the presence of the bleachable material, the contrast of the illumination that reaches the photoresist is increased. It is for this reason that the technique is called contrast enhancement. The degree to which the contrast is enhanced depends on both the photochemical properties of the bleachable material and the dose required to expose the underlying resist. The paper will discuss properties required of the bleachable material in order to make the technique feasible, such as the magnitudes of the extinction coefficient and the quantum yield. Bleaching experiments on candidate materials for the characterization of these parameters will be described. Also to be discussed is a model of the bleaching dynamics, which was used to calculate the improvements in contrast that are achieved as a function of base resist sensitivity. The extra processing steps required by the presence of the bleachable layer will be covered. Submicron resist patterns that demonstrate the resulting improvement in contrast will also be shown.

ISSN:0032-3888    

DOI:10.1002/pen.760231706

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe recent discovery that the photolysis of certain onium salts produces strong Brønsted acids presents a unique opportunity to design novel photoimaging systems based on these materials. For example, when used as photoinitiators, they can induce the negative image wise cationic polymerization of multifunctional epoxides, vinyl ethers, and lactones. Alternatively, they may be used to catalyze the degradation of hydrolytically sensitive polymers to give positive photoresists. The ability of still other onium salts to generate radical species as well as strong acids has been exploited to develop photoimaging processes which have no parallel in present photoresist technology. The processes consist of simultaneous radical polymerization and acid‐induced cationic polymerization. Finally, the recent observation that the onium salts can be dye‐sensitized allows them to be responsive to both the ultraviolet and visible regions of the spectrum and to be used with many commercial optical imaging sys

ISSN:0032-3888    

DOI:10.1002/pen.760231707

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractTo be efficacious as an x‐ray resist, a material must efficiently undergo a desirable chemical change upon being irradiated with x‐rays. The probability of such a change taking place is given by the product of the fractional x‐ray absorption and the “inherent sensitivity,” which we define as the yield per unit energy absorbed. Increasing the absorption of the polymer, as, for example, by chlorinating an olefin sulfone thereby increasing the absorption at wavelengths just below the chlorine absorption edge will result in improved usefulness if, and only if, this increased energy absorbed can be used by the polymer to enhance the desired chemical reaction. The “usefulness” of chlorinating is thus dependent on the efficiency of intramolecular energy transfer. We have studied the efficiency of this transfer by monitoring the loss of SO2from the main‐chain backbone as a function of absorbed x‐ray energy, using x‐ray wavelengths both abov and below the chlorine absorption edge. The polymers studied were 1‐olefin sulfones, with and without the chlorine atom in the ω‐position. Through the use of this series of polymers it was hoped to observe an effect due to the changing separation of the chlorine atom from the backbone. The experiments indicate that (a) the inherent sensitivity is independent of irradiating wavelength, for both the chlorine‐containing and the non‐chlorine‐containing polymers; (b) the hexene polymers are considerably more sensitive than the lower members of the series (which exhibit a sensitivity which is approximately independent of the side chain length); and (c) the chlorine‐containing polymers are less sensitive than the non‐chlorine‐containing species. At this time the explanation f

ISSN:0032-3888    

DOI:10.1002/pen.760231708

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractPoly(allyl methacrylate)‐co‐(hydroxyethyl methacrylate) has been evaluated as a high‐sensitivity, high‐resolution, high temperature‐resistant negative electron resist. The effects of molecular weight and polydispersity of the copolymer on its lithographic performance as an E‐beam resist were studied. The sensitivity of the copolymer is nearly constant in the weight‐average‐molecular‐weight range of 50,000 to 75,000, and it gradually decreases with a decrease in molecular weight. As expected for a negative resist, the resist contrast increases as the polydispersity is decreased. The sensitivity curve shape of the polymer was independent of the prebake temperature, which varied from 70 to 110°C, and of the various developers used. The exposed coating requires vacuum curing for image optimization. Resolution of 0.5 μm line/space pairs was obtained from a 0.6 μm thick resist by exposing the resist to 10 keV electrons with either a raster‐scan‐type or vector‐scan‐type electron‐beam exposure machine. After postbaking at 170°C, the resist had good resistance to both chemical etching and dry etching. The plasma‐etch resist

ISSN:0032-3888    

DOI:10.1002/pen.760231709

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper describes two types of cross‐linked positive‐working electron resists. The first is based upon phenol‐formaldehyde resins crosslinked to poly‐(methyl methacrylate) by phenolic ester groups. The second type is based upon polystyrene, crosslinked by carboxylic acid anhydride groups. The resist properties can be varied by changing the proportion of crosslinks. A version of the second type which contains about 95 percent styrene units is described. This material shows very good resistance to degradation in a plasma‐etching process for preparing chromium on glass masks, even when it is used as a very

ISSN:0032-3888    

DOI:10.1002/pen.760231710

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe polymerization kinetics, molecular parameters, and electron lithographic response of a series of copolymers of glycidyl methacrylate (GMA) and 3‐chlorostyrene (CLS) have been determined. The polymerization rate, molecular weight, and polydispersity decrease with increasing mole fraction of 3‐chlorostyrene (XCLS). Similarly, the sensitivity of this system decreases as the percentage of CLS in the copolymer increases. The value ofD g0.5for the copolymer containing 14.3 mole percent CLS is 0.45 μC/cm2increasing to 3.2 μC/cm2for the 54 percent CLS copolymer of equivalent molecular weight. On the contrary the wet air andO2plasma etch rates decrease asXCLSincreases. For example, the etch rate using wet air for PGMA is ∼ 30 percent greater than GMC (XCLS= 0.54). The post exposure polymerization rate decreases as the CLS content increases. The extent of the post cure reaction is dose dependent being a maximum atD g0.6= 0.64 μC/cm2for the copolymer containing 14.3 mole

ISSN:0032-3888    

DOI:10.1002/pen.760231711

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY