Quantum Lithography Based On Entanglement And Preparation Of Quantum States

With the development of modern industry, we need chips in a smaller and smaller size. Therefore it is imperative to improve the lithography so as to obtain much smaller pixels and correspondingly, much larger resolution. Optical lithography is brought about to meet such a requirement. In this disertation, different quantum states are studied and applied in optical lithography and the state preparation is discussed elementally. Meanwhile a series of significant results are obtained here.The first chapter introduces briefly the elementary theory of classical optical lithography and quantum optical lithography, and the main achievements in quantum lithography, in order to form a theoretical basis of our work in the following chapters. It is also pointed out here that the resolution obtained in general quantum lithographic methods is only N times larger than that achieved in classical lithography.In Chapter 2, we show our strategy where nonmaximally-entangled states (NMES) is used in quantum lithography explicitly. We also give the important results of our work as follows: 1. We generalize the quantum lithography with maximally entangled states(MES) to the one with nommaximally-entangled states. 2. We bring forward the concept of 'local entanglement' and 'nonlocal entanglement'. 3. We find that the increase of the nonlocal entanglement can cause the amplitude of exposure function larger and therefore we can control and manipulate the amplitude of exposure rate. 4. We draw the conclusion that the local entanglement of the two beams can improve the effective optical resolusion to X/8N, which is 2N times that obtained in classical methods. So we can etch 4N2 times as many pixels as we can in classical methods in the same area, which means the size of the chips is only 1/AN2 the size of the chips produced in classical methods. All these make a great improvement to quantum lithography. 5. We simulate the objective pattern -sin(x)- effectively, which makes it possible to etch curved circuits.While Chapter 3 shows us the quantum lithography with two-mode entangled coherent states.We calculate the exposure rate of the substrate in two-mode entangled coherentstates and find out that the increase of the amplitude of coherent state |a| or the N-photon-absorption sensitivity of the substrate can improve the exposure rate and the sharpness of the exposure pattern as well. It is worth noting that this kind of state is prepared relatively much more easily.Furthemore in Chapter 4, we discuss elementally the state preparation and show that less than (d - 1) x O(n2) single qubit operations and CNOT gates are sufficient to prepare an n-particle d-dimension superposition state from an n-particle classical state.In Chapter 5, a summary of the work and an outlook of this realm are given.