ISSN:0032-3888    

DOI:10.1002/pen.760322102

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThree positive working Si‐CARL resists for bilayer applications with oxygen‐RIE pattern transfer were investigated, and their lithographic performance at deep‐UV exposure was compared. With all three we obtained good focus latitudes for 0.35 μm lines and spaces ranging from 1.6 to 2.2 μm exposed with an 0.37 NA KrF‐excimer laser stepper. The zero bias exposure dose required for resist R1, of the diazodiketone type, is relatively high (70 mJ/cm2), but R1 has the advantage of not suffering from linewidth fluctuations caused by post‐exposure delay time effects. Processing for resists R2 and R3, which are based on acid catalyzed deprotection of t‐BOC‐imide and t‐butylester, respectively, had to be optimized to avoid bridging of isolated spaces after Chemical Amplification of Resist Lines (CARL). This bridging is caused indirectly by evaporation of triflate acid during PEB. Resist R2 needs only 8.5 mJ/cm2for exposure but has a poor linewidth increase after CARL, which seems to be the reason for eroded 0.25 μm patterns after oxygen‐RIE. Resist R3 shows the steepest resist slopes and the best overall performance. The ultimate resolution for resists R1 and R3 is 0.25 μm, which, according to the Rayleigh equation for resolution, corresponds

ISSN:0032-3888    

DOI:10.1002/pen.760322103

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThe lithographic performance of chemically amplified positive resists depends on controlling the delay time between the exposure and post‐exposure bake (PEB) process steps. The effect of post‐exposure delay (PED) was investigated in poly(t‐butoxycarbonyloxystyrene‐sulfone) formulated with photoacid generators (PAG) by a variety of analytical techniques including Rutherford backscattering, infrared, X‐ray photoelectron and laser ablation microprobe mass spectrometry. The results indicate that the base‐insoluble residue formed during PED is primarily a surface phenomenon and is a result of incomplete deprotection at the resist surface. It was determined that ppb levels of basic vapors present in the resist processing environment affect process performance profoundly by reacting with the photogenerated acids during PED. Isolation of resist surface from the immediate environment by means of a thin, acidic, and base‐soluble overcoat (covercoat) material dramatically alleviates the environmental effects by quenching basic airborne contaminants and improves

ISSN:0032-3888    

DOI:10.1002/pen.760322104

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

Abstractt‐Boc protected Deep‐UV transparent polymers with photoacid generators have been widely investigated as potential positive deep‐UV resist systems. However, utility of these systems is seriously handicapped by environmental contaminants leading to an insoluble “surface skin” formation. Only with a specially controlled environment or by use of an “overcoat” material is the performance of these systems acceptable. We have investigated a series of t‐Boc protected poly(styrene‐maleimide) copolymers and poly(hydroxy styrene) polymers with onium‐salts. Upon incorporation of a special class of organic additive, the surface effects inherent to these positive deep‐UV systems are significantly reduced thereby avoiding any extraneous precaution of protecting the resist surface from a typical manufacturing environment. We evaluated these t‐Boc polymer/onium‐salt systems with different additives under a varied set of processing conditions. In addition, plausible structure‐activity relationship of these additives in controlling the s

ISSN:0032-3888    

DOI:10.1002/pen.760322105

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractWe describe here performance enhancements provided by an anti‐reflective coating (ARC), developed for deep UV applications. The reduction in substrate reflections provided by the ARC layer results in significant increases in resolution capability and process latitude compared to single layer deep UV resist. Increased linewidth control and patterning capability for highly reflective, grainy, and topographical substrates is demonstrate

ISSN:0032-3888    

DOI:10.1002/pen.760322106

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have studied the imaging characteristics of an excimer laser stepper as a function of laser wavelength. Focus, magnification, distortion, CD process window, and laser performance were all examined, and an operating wavelength was selected. The self‐metrology capabilities of both the laser and stepper were tested to insure that the system would set itself to the correct wavelength upon initialization, and maintain that setting during volume production activity. The use of an on‐line stepper image sensor to evaluate the quality of the aerial image, coupled with the built‐in wavelength tracking system as part of the laser optics, was found to provide the required closed loop system for wavelength and focus control. Based on these experiments, we have determined that a quick aerial image check before each production lot should suffice to insure focus control of better than 0.25 microns and magnification errors less than 15 nm during the entire time required to expose th

ISSN:0032-3888    

DOI:10.1002/pen.760322107

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractIn our current work, we have examined the e‐beam sensitivity and thermal processing behavior of pure PBOCST [poly(tert‐butoxycarbonyloxystyrene)]. An alkali soluble latent image can be generated in the PBOCST by e‐beam exposure followed by a post‐exposure bake (PEB) at relatively high temperatures (140 to 150°C). Pattern wet development operates on the same basis as a PBOCST/acid generator two component system. Deprotection, accelerated by the exposure, yields alkali soluble areas, while unexposed areas remain insoluble. Sensitivities of 5 to 10°C/cm2and contrasts of 6 to 10 have been measured. Complete TBOC deprotection results in a film thickness loss of 35 to 40% as CO2and isobutene are evolved. A laser interferometer/hotplate setup was used to track film thickness with time during the thermal deprotection process. IR analysis confirmed the correlation between conversion and thickness. It was found that a slow initial conversion rate was followed an exponentially steep rise in rate after 50% conversion. Activation energies were on the order of 30 kcal/mol. It was concluded that thermolysis in both exposed and unexposed resist occurred during the PEB, but that the difference in extent of conversion on exposure was sufficient to generate

ISSN:0032-3888    

DOI:10.1002/pen.760322108

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractIrradiation of certain organosilicon polymers with a 193‐nm excimer laser forms a latent image that contains increased amounts of oxygen. Patterning is achieved by dry development in an HBr plasma, where the oxidized polymer etches more slowly than the unexposed areas. With these polymers as the top layer in a bilayer resist scheme, 0.2 μm resolution has been demonsrated and resist sensitivities less than 50 mJ/cm2have been achieved. Three classes of organosilicon layers have been investigated: polysilynes; polysilanes, in particular poly(phenylmethyl) silane; and a plasma‐deposited polymer derived from tetramethylsilane (PPTMS). The PPTMS, when used with plasma‐deposited planarizing layers, opens the possibility of an all‐dry, cluster‐tool‐compatible lithog

ISSN:0032-3888    

DOI:10.1002/pen.760322109

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractThe advantages of surface‐imaging photoresist processes have been well documented; it has shown to have greater resolution, wider focus budget, and less sensitivity to topography and reflections from the substrate. The DESIRE process (Diffusion Enhanced Silylated Resist) is a good example of a surface‐imaging process. In previous papers we have described the characterization of this process in a lab environment, discussed some of the issues involved in the implementation of this process in a manufacturing environment, and more recently presented results from its implementation in a dynamic random memory, DRAM, manufacturing environment. A large of knowledge must be acquired and disseminated in the process of implementing a new technology in a manufacturing environment. This is particularly true in the semiconductor industry because of the large and complex interactions that exist between the process and the electronic characteristics of the devices. Even within the same process, complex interactions between the different steps can take place. Such is the case with the DESIRE process. Over the past few years a great deal of “know‐how” has been acquired in the course of implementing this technology in a DRAM wafer fab of Texas Instruments in Dallas, Tex. We present here two selected cases where such complex interactions have been investigated: (1) radiation damage that might take place during the dry‐development step of this process, and (2) the effect of the equipment and material on the electrical discharge, or arcing, during dry

ISSN:0032-3888    

DOI:10.1002/pen.760322110

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY

摘要:

AbstractAu patterns are formed by photographical patterning of polymeric Au mercaptoterpenes (Au resinate), followed by bakeout of the Au resinate patterns to remove carbonaceous materials. Since commercially available Au resinate is not sensitive to 436 nm (g‐line) light and cannot be photographically patterned, we mixed azide (photocrosslinker) with Au resinate to give photosensitivity to the g‐line. The mixture of Au resinate and azide was spun on an Si substrate, and then exposed with 436 nm (g‐line) light by a standard contact printing technique. Upon exposure, Au resinate was crosslinked by the reaction with azide, and became insoluble. Au resinate patterns were generated by development with monochlorobenzene. On baking out the Au resinate patterns to remove carbonaceous materials, we obtained 2 μm line and space Au patterns. The conductivity of the Au patterns obtained was 1/4 that of bulk Au. For a mask repair application, we mixed Cr resinate with a mixture of Au resinate and azide to improve the adhesion of the resulting metal patterns onto the quartz plate. The transmittance and the adhesion were found to depend on the bakeout condition and the mixing ratios of the Cr resinate. Bakeout in vacuum with 0.1 torr oxygen gave far better adhesion and opaqueness than bakeout in air, because of residual carbon in the resultant metal. Mask repair was carried out at the optimized condition by using a spot exposure system. The clear defect was repaired with the transmittance<1% and good ad

ISSN:0032-3888    

DOI:10.1002/pen.760322111

出版商:Society of Plastics Engineers    

年代:1992

数据来源: WILEY