Holographic lithography is a new technique developed for the fabrication of threedimensional photonic crystals in polymer. Four coherent laser beams are interfered to generate a three-dimensionally periodic interference pattern in a film of photoresist. Subsequent processing steps render a three-dimensional photonic crystal, whose structure is commensurate with the original interference pattern. Two interference patterns are discussed in detail: a face-centred cubic pattern with a conventional lattice constant of 922nm in air and a face-centred cubic pattern with a conventional cube side of 397nm in air (interference wavelength 355nm). Three types of basis are presented for the interference pattern with a 922nm lattice constant: a righthanded, a left-handed and a non-chiral basis. Photonic crystals have been fabricated with both a chiral and a non-chiral basis and evaluated by scanning electron microscopy. Optical transmission measurements are presented for the non-chiral photonic crystals and are interpreted in both a Bragg scattering model and a photonic bandstructure model. A 'GaAs' and a 'diamond' basis are presented for the interference pattern with a 397nm lattice constant. Photonic crystals have been fabricated with the 'GaAs' basis and evaluated by scanning electron microscopy.

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Liang, Hui = 纳米线器件的制备和表征 / 梁慧. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 45-48). / Abstracts in English and Chinese. / Liang, Hui = Na mi xian qi jian de zhi bei he biao zheng / Liang Hui. / Chapter Chapter 1 --- Nanowire-based devices --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Properties of various nanowires --- p.2 / Chapter 1.1.2 --- Nanowire growth methods --- p.3 / Chapter 1.1.3 --- Introduction to EBL --- p.4 / Chapter 1.1.4 --- Properties of nanowire and the arrays and related devices --- p.6 / Chapter Chapter 2 --- Experimental --- p.9 / Chapter 2.1 --- Nanowire preparation --- p.9 / Chapter 2.1.1 --- ZnS nanowire growth --- p.9 / Chapter 2.1.2 --- Sb2S3 nanowire growth --- p.10 / Chapter 2.2 --- Device fabrication --- p.10 / Chapter 2.2.1 --- Single-nanowire device --- p.10 / Chapter 2.2.2 --- Multiple-nanowire device --- p.17 / Chapter 2.2.3 --- Silicon device --- p.17 / Chapter 2.3 --- Characterizations --- p.18 / Chapter 2.3.1 --- Morphological and structural characterizations of the nanowires --- p.18 / Chapter 2.3.2 --- Two-probe measurements --- p.18 / Chapter 2.3.3 --- Four-probe measurements --- p.19 / Chapter Chapter 3 --- Results and Discussion --- p.21 / Chapter 3.1 --- Optimal factors for sample preparation --- p.21 / Chapter 3.1.1 --- Trial of spin coating --- p.21 / Chapter 3.1.2 --- Trial of Coating thickness --- p.21 / Chapter 3.1.3 --- Trial of e-beam lithography --- p.22 / Chapter 3.1.4 --- Trial of dosage --- p.23 / Chapter 3.1.5 --- Trial of development time --- p.26 / Chapter 3.2 --- Electrical Properties of devices made --- p.28 / Chapter 3.2.1 --- UV-visible response of single ZnS nanowire devices --- p.28 / Chapter 3.2.2 --- The optoelectronic characteristics of single Sb2S3 nanowire devices --- p.32 / Chapter 3.2.3 --- The optoelectronic characteristics of multiple-nanowire devices --- p.35 / Chapter 3.2.4 --- Temperature dependent resistance and magnetoresistance of the silicon device --- p.41 / Chapter Chapter 4 --- Conclusions --- p.44 / Chapter Chapter 5 --- References --- p.45

The history of printing is dominated by studies of mechanical typography. In this thesis the role of lithography in modernising printing is presented as an alternative path. The conventional explanation of how different printing processes work is generally made by dividing them into relief, intaglio and planographic processes. This explanation is of questionable value now, in a world where digital pre-press and offset printing hold sway. It is an outmoded idea to think that different ways of delivering ink under pressure is at the core of printing. Instead, it is more useful to focus our attention on the role played by direct and indirect image transfer. The similarities between the uses made by Gutenberg and Senefelder of direct and indirect image transfer has a greater importance than has the simplified division of printing processes into classes based upon depth of impression which is, essentially, a mechanical idea grounded in the typographic tradition. The idea presented here is that Gutenberg's application of indirect image transfer in his invention of moveable type provoked changes of greater importance than did the alternative invention of printing illustrations directly from metal plates or wooden blocks. Similarly, direct lithography was transformed by Senefelder into a vehicle for indirect image transfer by the invention of lithographic transfer paper. This invention had important ramifications for the future of lithography and for the preservation of photographic images. The combination of chemical printing and indirect image transfer made the capture of photographic images possible for the first time. In the nineteenth century, lithography also provided the first means by which photographs could be reproduced with printing ink in books - typography following here rather than leading the way. These issues have not been clearly recognised by many. The widely acknowledged superiority of typography to print economically, sharply, and at speed, was not surpassed by lithographers (who tended to concentrate on technical illustration and decorative printing) for many years. It was not until indirect image transfer was applied to the lithographic press that this barrier to progress was overcome, and, at last, text and image were efficiently transferred photographically to the rotary offset press.

In this thesis, we use E-Beam lithography to finish the process of DBR laser, 2D Photonic crystal, and Metallic nanoelectrodes. We use the new E-Beam system to define array patterns. By this test, we obtain the minimum linewidth of 50nm, and the maximum working range is 250£gm*250£gm. We fabricated the 2D photonic crystal microcavity and DBR laser on the InGaAs/InAlGaAs which was grown by molecular beam epitaxy (MBE) on InP substrate. For the DBR laser, the length of Multi-mode Interference (MMI) was 90£gm to satisfied the emission wavelength and optical modes. We apply a coupled DBR reflector on both sides of MMI. The mirror width was 361nm and the air gap was 388nm. For the 2D photonic crystal (2D PhC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 1137nm and 456nm, respectively. The TE-mode photonic band gap of this structure is corresponding to wavelength range in 1517.01 nm~1617.81 nm. We leave a single defect in the 2D PhC to form 2D PhC microcavity and the corresponding defect modes are 1546.32nm and 1547.74nm. The Micro-PL measurement shows that a defect mode at 1547nm (a/£f=0.74), a surface state at 1351nm (a/£f=0.85), and a standing wave at 1480nm (a/£f=0.78). The maximum Q value is about 400 for the defect mode.

Moore’s Law has driven a continuous demand for decreasing feature sizes used in Very Large Scale Integrated (VLSI) technology which has outpaced the solutions offered by lithography hardware. Currently, a light wavelength of 193nm is being used to print sub-65nm features. This introduces process variations which cause mismatches between desired and actual wafer feature sizes. However, the layout which affects the printability of a circuit can be modified in a manner which can make it more lithography-friendly. In this work, we intend to implement these modifications as a series of perturbations on the initial layout generated by the CAD tool for the circuit. To implement these changes we first calculate the feature variations offline on the boundaries of all possible standard cell pairs used in the circuit layout and record them in a Look-Up Table (LUT). After the CAD tool generates the initial placement of the circuit, we use the LUT to estimate the variations on the boundaries of all the standard cells. Depending on the features which may have the highest feature variations we assign a cost to the layout and our aim is now to reduce the cost of the layout after implementing perturbations which could be a simple cell flip or swap with a neighboring cell. The algorithm used to generate a circuit placement with a low cost is Simulated Annealing which allows a high probability for a solution with a higher cost to be selected during the initial iterations and as time goes on it tends closer to the greedy algorithm. The idea here is to avoid a locally optimum solution. It is also essential to minimize the impact of the iterations performed on the initial solution in terms of wirelength, vias and routing congestion. We validate our procedure on ISCAS85 benchmark circuits by simulating dose and defocus variations using the Mentor tool Calibre LFD. We obtain a reduction of greater 20% in the number of instances with the highest cell boundary feature variations. The wirelength and the number of vias showed an increase of roughly 2.2-8.8% and 1.2- 7.8% respectively for different circuits. The routing congestion by and large remains unaffected.

In this thesis, we fabricated the 2D photonic crystal and modified 1D photonic crystal microcavity on the InGaAs/GaAs substrate by E-beam lithography. The wafer are grown by molecular beam epitaxy (MBE) on GaAs substrate. The active layer consists of six InGaAs quantum wells at 1050nm emission wavelength. For the 1D photonic crystal microcavity (DBR laser),we changed the cavity shape and length to match the mode of light in the cavity. It can increase the reflectivity of the laser. In our simulations, we scanned different cavity length and found the corresponding data. We designed two and three pairs of DBRs formed on the edge of laser cavity, respectively. The cavity length is 121µm and the mirror width is 230nm and the air gap is 263nm. For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 742nm and 304nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1026nm ~ 1089nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1051.58nm¡B1053.39nm and 1054.87nm. In addition, we reduced the air columns around the cavity and simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process.

In this thesis, we fabricated the 2D photonic crystal microcavity and laterally coupled distributed feedback laser on InGaAs/InAlGaAs wafers by E-beam lithography. We also fabricated the 2D photonic crystal microcavity on the InGaAs/GaAs substrate at 980nm emission wavelength. The wafer are grown by molecular beam epitaxy (MBE). For the laterally coupled distributed feedback laser (LC-DFB laser) , we changed the grating shape and length to form proper grating, and it will make constructive diffraction and coupling. We design the mirror width is 180.55nm and the air gap is 541.65nm. For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 1139nm and 456nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1522.72nm~1617.89nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1549.23nm and 1550.08nm. We have simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process. Also, we can use the same method to fabricate 980nm photonic crystal.