Spie Newsroom最新文献

{"title":"Plasma etch challenges for next-generation semiconductor manufacturing","authors":"V. Rastogi, P. Ventzek, A. Ranjan","doi":"10.1117/2.1201706.006842","DOIUrl":"https://doi.org/10.1117/2.1201706.006842","url":null,"abstract":"In the photolithography process, a requisite mask layout is printed into a polymer layer. This layer, in turn, is transferred onto underlying inorganic/organic material layers for the fabrication of 3D semiconductors, and for high-volume integrated-chip manufacturing. Moore’s law describes a trend, first observed in 1965, in which the dimension of patterns in these layouts shrinks every two years, doubling the number of transistors on the microchip. Optical lithography has long since reached its physical limit (i.e., printing feature sizes below 40nm), and a number of alternative printing/material deposition schemes have been evaluated for use below this limit (see Figure 1) to maintain the economy of scaling. Among these schemes, plasma etching (which transfers the printed mask layout onto underlying layers by initiating chemical reactions) is employed industrywide. Plasma is partially ionized gas (i.e., which contains gas atoms/molecules, activated radicals, and ions). The dry plasma etching process involves interactions—between radicals and the exposed surface—which lead to the removal/volatilization of the activated/modified layer via energetic ion bombardment. To optimize the etch process, the pressure, gas flow/flow ratios, radio frequency power, and substrate temperature can be modified by adjusting the appropriate tuning knobs. When one of these tuning knobs is adjusted, change is triggered in more than one of the plasma parameters (i.e., the radical flux, ion flux, ion energy, and ion energy distribution). In a continuous plasma-etch process, surface modification (activation) and energetic material removal (desorption) occur concurrently. Concurrence is problematic, however, because changing plasma parameters to improve one aspect of the printed mask transfer may degrade Figure 1. Alternative patterning schemes able to achieve feature sizes of less than 40nm: 193nm immersion lithography combined with selfaligned multiple patterning; extreme UV (EUV) lithography; and directed self-assembly (DSA). Each color represents a different material layer. SADP: Self-aligned double patterning. SAQP: Self-aligned quadruple patterning. SAOP: Self-aligned octuple patterning.1","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83795651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing plasmonic resonance properties in the near-IR","authors":"D. Look","doi":"10.1117/2.1201704.006849","DOIUrl":"https://doi.org/10.1117/2.1201704.006849","url":null,"abstract":"Surface plasmon polaritons (SPPs) are electromagnetic waves that arise when a plasmon wave1–5 (i.e., a coordinated swarm of electrons) interacts strongly with a light wave of a similar frequency (!), and together they are confined to, and propagate along, an air/metal interface. SPPs are of substantial interest because it is possible to control and modify them with the use of normal circuit elements, to allow the SPP to be ejected as pure light. In addition, the dimensions of SPPs are much smaller in metals than in air, and so the usual diffraction limit of light in air does not apply. The confinement property of SPPs—which can lead to intense electric fields and enhanced light emission—is thus exploited in a number of applications, including surfaceenhanced Raman spectroscopy (which has a higher resolution than standard Raman spectroscopy). The metals that are generally used in plasmonic applications (gold and silver), however, are not ideal for all energy ranges. Although these materials have high electron concentration (n) values (mid1022cm 3), and work well in the UV (3–12eV) and visible (1.5– 3eV) ranges (because !p n1=2), they experience heavy losses in the near-IR region (0.5–1.5eV). This is because the loss is proportional to n/! (where is electron mobility), and the high value of n cannot be avoided. In response to this problem, it has previously been proposed1–3 that highly doped semiconductors, with smaller n values, may be better plasmonic materials (than the standard gold and silver) in the near-IR (NIR) region. Fortunately— mainly because of the need for transparent electrodes in LEDs, display circuits, and solar cells—the field of highly doped semiconductors is well developed.6 However, the goal in transparent electrode design is generally to have the highest possible n, whereas in plasmonic applications, it is to have the lowest possible n, but that is still high enough to produce the desired resonance wavelength ( res). The best possible material is thereFigure 1. Experimentally measured plasmonic resonant wavelength ( res) of gallium-doped zinc oxide (GZO) as a function of annealing temperature (TA).","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86840294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel concept for extreme-UV photoresist materials","authors":"W. Montgomery, A. Robinson","doi":"10.1117/2.1201705.006883","DOIUrl":"https://doi.org/10.1117/2.1201705.006883","url":null,"abstract":"For several years, extreme-UV (EUV) lithography—i.e., at a wavelength of 13.5nm—has been talked about as the next enabling technology for lithographic patterning. However, a number of technological stumbling blocks (i.e., issues with EUV optics, photomask infrastructures, and photoresist materials) have delayed the widespread introduction and implementation of this technique. For instance, the scanner optics that are used in patterning systems and photomasks have been changed from transmissive optics to reflective optics. This change has proven to be a rather challenging transition, but tremendous progress has now been made and EUV scanner shipments are taking place at an accelerated pace. EUV pellicle development is also progressing (a mitigation step necessary to address defect concerns), and mask infrastructures are being developed at both merchant and in-house mask shops. To meet the requirements for new EUV-suitable photoresist materials, photoresist manufacturers originally reformulated extant 193nm resist systems—via the use of formulation adjustments, additives, and photoacid generator (PAG) loading—for EUV use. Although this is a cost-effective approach, it brings line width roughness (LWR), sensitivity, and resolution limitations. LWR is defined by the random fluctuations in the width of a patterned lithographic feature along its length. As photoresists are used to print smaller and smaller patterns, the imperfections in the sidewall become a larger part of the patterning error. Moreover, in several previous studies, these high LWR values have been attributed to the use of polymers for the photoresist matrix. Other contributing factors to the LWR values are shot noise (e.g., flux variations, which are increasingly important because the dose per photon increases substantially in the EUV regime), PAG location in the bulk film (relative to the acid-sensitive protecting group), acid diffusion (or blur) during the chemical amplification process, and the level of developer selectivity. Figure 1. Schematic representation of (a) the traditional chemical amplification approach used for 193 and 248nm photoresist extension materials in extreme-UV patterning. The multitrigger concept for (b) a high-dose area and (c) a low-dose area is also illustrated.","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84264454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate self-calibration of advanced metrology and measurement systems","authors":"T. Sandstrom, John-Oscar Larson, Peter Henriksson, M. Ekholm, M. Wahlsten","doi":"10.1117/2.1201706.006710","DOIUrl":"https://doi.org/10.1117/2.1201706.006710","url":null,"abstract":"In recent years there has been a rapid development of display technologies, with ever higher pixel density and ever smaller feature sizes being achieved. For example, modern smartphone displays now have densities of more than 800 pixels per inch (ppi) and have pattern elements down to 1.5 m (and they are likely to become even denser in the future).1, 2 These display improvements, however, have also given rise to dramatically higher photomask technology requirements. Indeed, in high-volume production for state-of-the-art displays, many mobile screens are exposed simultaneously from a meter-sized photomask.2 The associated requirements for the overlay precision (i.e., accuracy of lateral dimensions) are quite formidable. To verify the geometry of photomasks used for the production of smartphone screens, we have previously developed a metrology tool—known as the Prexision Mask Metrology System (Prexision-MMS)—which can be used for mask sizes up to that of Generation 8 (G8), i.e., 120","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82487897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray technique for determining chemical disorders in complex alloys","authors":"F. Tsui, B. Collins, Y. Chu","doi":"10.1117/2.1201704.006875","DOIUrl":"https://doi.org/10.1117/2.1201704.006875","url":null,"abstract":"Complex alloys and compounds possess an impressive array of properties and functionalities. These features often emerge from the particular ordering of constituent atoms within the crystal lattice (i.e., the chemical ordering). One key challenge for studying these materials is the ability to characterize chemical disorders that can alter, suppress, or enhance such unique functionalities. An ability to determine the distribution of the constituent atoms in complex alloys is therefore of critical importance for the materials community. Such measurements have been nearly impossible to perform in alloys that contain atoms with comparable sizes (‘similar’ atoms, i.e., in terms of atomic number and bond length). This difficulty arises primarily because conventional charge-scattering techniques (e.g., x-ray and electron) lack the sensitivity required to differentiate between similar atoms. For this reason, there is confusion in the literature regarding various ‘related’ or ‘indistinguishable’ structures (i.e., where similar atoms that occupy different lattice sites correspond to different crystalline symmetries but the structural differences may or may not be detectable experimentally). The problem is further amplified because there are a large number of alloys with two or more constituent elements that belong to the same row in the periodic table. To overcome these issues, we have recently developed an x-ray diffraction (XRD) technique called multiple-edge anomalous diffraction (MEAD).1 Our approach is based on tracking the diffraction intensity versus the x-ray energy through multiple absorption edges of the constituent elements. At energies near the absorption edge, anomalous dispersion and absorption cause variations in the atomic form factor, effectively causing the Figure 1. The Heusler compounds and related lattice structures. Four interpenetrating face-centered cubic (FCC) sub-lattices are each occupied by a specific element positioned at [000], [ 12 00], [ 1 4 1 4 1 4 ], and [ 14 1 4 3 4 ]. In the full Heusler L21 structure (Cu2MnAl-type, i.e., two parts copper, one part manganese, and one part aluminum), copper atoms occupy the Aand C-sites, and manganese and aluminum atoms occupy the Band D-sites, respectively. In the ‘inverse’ Heusler X structure (CuHg2Ti-type, i.e., one part copper, two parts mercury, and one part titanium), mercury atoms occupy the Aand B-sites, and copper and titanium atoms occupy the Cand D-sites, respectively. In the quaternary Y structure (LiMgPdSn-type, i.e., one part lithium, one part manganese, one part palladium, and one part tin), each element occupies a specific FCC sub-lattice.","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85431923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrons interacting with metamaterials: from few-photon sources to electron optics","authors":"N. Talebi","doi":"10.1117/2.1201705.006891","DOIUrl":"https://doi.org/10.1117/2.1201705.006891","url":null,"abstract":"Controlling the trajectory of moving electrons by means of highly efficient aberration-corrected magnetic lenses1 has paved the way toward ultrahigh resolution microscopy and diffraction. Additionally, the advent of ground-potential monochromators has pushed electron spectroscopy into a new era (i.e., where electron energy-loss spectroscopy achieves an unprecedented energy resolution, as high as a few meV).2 Moreover, teaming up electron guns and lasers has enabled a number of new technologies, including ultrafast characterization of optical near fields,3 dielectric laser accelerators,4, 5 and photon-induced near-field electron microscopy.6 As in optics, ultrafast electron microscopy could be further advanced by exploiting time-frequency analysis.7 An example of methods that could stand to benefit from this approach are interferometry techniques, which provide unprecedented knowledge of the spatial profile of electron-induced optical near-field and electronic states in the time-energy phase space. Such insight could enable an understanding of the transition between states and of temporal evolutions (e.g., dephasing). To achieve this in optical studies, the time resolution has generally been increased (i.e., to the attosecond era). This is not feasible with today’s photoemission electron guns, however, due to time jitter. We have developed a new technique for overcoming these shortcomings by enabling the electron to create its own conjugate photons.8 A fast electron (i.e., traveling at 70% of the speed of light) can interact with a precisely designed metamaterial-based electron-driven photon source (EDPHS) to create broadband, coherent, and focused transition radiation: see Figure 1. Figure 1. A fast electron interacting with the electron-driven photon source (EDPHS) can create an ultrafast optical pulse with an energy range of 1–6eV. The EDPHS emission can excite the sample (here a silver disc) and interfere with the electron-induced excitations in the sample. e-: Electron. h̄!: Photon energy.","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90343513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-loss transmission of multimode polymer optical waveguides","authors":"T. Amano, A. Noriki","doi":"10.1117/2.1201702.006853","DOIUrl":"https://doi.org/10.1117/2.1201702.006853","url":null,"abstract":"","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87089706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solving complex optimization problems with a coherent Ising machine","authors":"H. Takesue, T. Inagaki, T. Honjo","doi":"10.1117/2.1201702.006859","DOIUrl":"https://doi.org/10.1117/2.1201702.006859","url":null,"abstract":"As the various systems in our society grow larger and more complex, their analysis and optimization grow increasingly important. Many such tasks are classified as combinatorial optimization problems, which can be mapped onto the ground-statesearch problems of the Ising model.1 Recently, several approaches to simulating the Ising model have been demonstrated using artificial spin networks, such as superconducting quantum bits (qubits)2 and CMOS devices.3 These physical Ising machines have suffered from a limited number of spin-spin couplings, however, because of the use of solid-state devices as artificial spins. We have realized a coherent Ising machine (i.e., an artificial spin network based on quantum electronics technologies, CIM) that is instead based on photonics.4 To achieve this, we used time-multiplexed degenerate optical parametric oscillators (DOPOs)5, 6 as artificial spins, and realized all-to-all coupling between 2048 DOPOs using a measurement-feedback scheme.7 We experimentally confirmed that our CIM can find solutions for NP-hard maximum cut problems of a 2000-node complete graph.4 The setup of our CIM is illustrated in Figure 1. A periodically poled lithium niobate (PPLN) waveguide module is placed in a fiber ring cavity, which includes a 1km fiber delay line, an optical bandpass filter, optical couplers, and a fiber stretcher for cavity-phase stabilization. When we inject pump pulses with a wavelength of p into the PPLN waveguide, pulsed spontaneous emission noise begins circulating in the cavity. If we limit the wavelength component to 2 p using the optical bandpass filter, parametric amplification occurs only at signal-idler degeneracy, i.e., where only lights with 0 or phase components Figure 1. The setup of our coherent Ising machine (CIM). The optical bandpass filter and fiber stretcher in the cavity are not shown for conciseness. FPGA: Field-programmable gate array. OPO: Optical parametric oscillator. PPLN: Periodically poled lithium niobate.","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84883450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing flash lidar detector options","authors":"P. McManamon, P. Banks, J. Beck, Dale G. Fried, A. Huntington, E. Watson","doi":"10.1117/2.1201707.006466","DOIUrl":"https://doi.org/10.1117/2.1201707.006466","url":null,"abstract":"Lidar (light detection and ranging) is a method of surveying based on pulsed laser light that is becoming very common. It is used by the military and by many commercial applications, such as 3D mapping and navigation in autonomous cars and unmanned air vehicles. For these applications, sensitive lidar detectors are essential. But there are different types of lidar detection schemes, with corresponding strengths and weaknesses. Here, we compare three lidar receiver technologies using the total laser energy required to perform a set of imaging tasks (a more detailed description is available elsewhere1). The tasks are combinations of two collection types (3D mapping from near and far), two scene types (foliated and unobscured), and three types of data products (geometry only, geometry plus 3-bit intensity, and geometry plus 6-bit intensity). The receiver technologies are based on indium gallium arsenide (InGaAs) Geiger mode avalanche photodiodes (GMAPDs) (see Figure 1), both InGaAs and mercury cadmium telluride (HgCdTe) linear mode avalanche photodiodes (LMAPDs), and optical time-of-flight (OTOF) lidar using commercial 2D cameras. This last method combines rapid polarization rotation of the image and dual lowbandwidth cameras to generate a 3D image. We chose scenarios to highlight the strengths and weaknesses of the various lidars. Table 1 summarizes the energy required for various imaging modalities. For the case of the InGaAs LMAPDs, we actually carried two bandwidth settings, but in the table we list only the bandwidth setting that required lower energy. GMAPD cameras operate with a low probability of return (i.e., reflection) on a single pulse, but require multiple coincident returns from the same range. The GMAPD cameras do well with bare-earth 3D mapping and 3D imaging through trees. In grayscale situations, the GMAPD cameras use somewhat more energy. The advantages of the GMAPDs are the following: they are thermoelectrically (TE) cooled; they are low energy per pulse, high-rep-rate lasers, Figure 1. Schematic illustration of a diffused-junction planar-geometry avalanche diode structure. This is the structure for one of our detector options, the Geiger mode avalanche photodiode (GMAPD). The electric field (E) profiles at right show that the peak field intensity is lower in the peripheral region of the diffused p-n junction than it is in the center of the device. SiNx: Silicon nitride. i-InP: Indium phosphide p-i-n diode. i-InGaAsP: Intrinsic (i.e., this region of the semiconductor wafer is not intentionally doped either por n-type) indium gallium arsenide phosphide.","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90734933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated metasurface chip for versatile polarization generation","authors":"P. Wu, W. Tsai, W. T. Chen, Yao-Wei Huang, Ting-Yu Chen, Jia-Wern Chen, C. Y. Liao, C. H. Chu, G. Sun, D. Tsai","doi":"10.1117/2.2201707.01","DOIUrl":"https://doi.org/10.1117/2.2201707.01","url":null,"abstract":"","PeriodicalId":22075,"journal":{"name":"Spie Newsroom","volume":"137 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76606357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}