In this paper we presented a pulse shaping technique on regular solid-state lasers and the application in semiconductor micromachining. With a conventional Q-switched laser, all of the parameters can be adjusted over only limited ranges, especially the pulse width and pulse shape. However, some laser link processes using traditional laser pulses with pulse widths of a few nanoseconds to a few tens of nanoseconds tend to over-crater in thicker overlying passivation layers and thereby cause IC reliability problems. Use of a laser pulse with a special shape and a fast leading edge, such as tailored pulse, is one technique for controlling link processing. The pulse shaping technique is based on light-loop controlled optical modulation to shape conventional Q-switched solid-state lasers. One advantage of the pulse shaping technique is to provide a tailored pulse shape that can be programmed to have more than one amplitude value. Moreover, it has the capability of providing programmable tailored pulse shapes with discrete amplitude and time duration components. In addition, it provides fast rising and fall time of each pulse at fairly high repetition rate at 355nm with good beam quality. The regular-to-shaped efficiency is up to 50%. We conclude with a discussion of current results for laser processing of semiconductor memory link structures using programmable temporal pulse shapes. The processing experiments showed promising results with shaped pulse.

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We report on recent advances in the development of a 1064 nm pulsed master oscillator fiber power amplifier (MOFPA) with integrated modulators enabling programmable temporal pulse shapes and its employment in a tandem photonic amplifier. The MOFPA amplifier chain is seeded by a laser diode operated in the CW regime, yielding very stable spectral characteristics that are independent of the pulse repetition rate and pulse shape. The use of 3 GHz integrated LiNbO3 electro-optic modulators in conjunction with high speed digital electronics results in an excellent pulse shaping capability, a fine pulse amplitude stability and high repetition rate operation (100 kHz-1MHz) with fast rise times (<1ns). Energy per pulse of 8-10 µJ with good beam quality characteristics are obtained using advanced large mode area (LMA) fiber designs in the final power amplifier stage. The output is linearly polarized with a spectral bandwidth of < 0.1 nm. When employed in a tandem amplifier configuration, in which the MOFPA output is input to a single-stage, single-pass Nd:YVO 4 amplifier pumped by a single 30 W fiber-coupled 808 nm diode, a 600 mW average power at 100 KHz signal input from the MOFPA was amplified to 6 W with faithful amplification of the input temporal pulse profile while achieving excellent beam quality (M 2 <1.1) and pulse amplitude stability (< ±3%, 3σ). A model of tandem amplifier performance shows good agreement with experimental results and indicates prospective performance of advanced tandem photonic amplifier configurations.

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