For semiconductor manufacturing, a mature industry, a number of laser techniques are employed in production. Diodepumped
solid-state (DPSS) lasers are used in applications that cannot be performed by mechanical, chemical, or other
laser fabrication methods as well as where they add value through increased throughput and/or improved process quality.
Applications such as edge isolation, wafer scribing/dicing, via formation, laser doping and annealing for Semicon are
being applied to crystalline silicon PV manufacture as well as research and development for the next generation of high
efficiency cells. Similarly, selective material removal for exposing underlying layers without thermal damage is vital in
the production of thin film PV panels. In this paper, some of the most important applications of lasers along with
experimental results will be reviewed to illustrate how laser methods can have a significant impact on the development
and productivity of the photovoltaic industry.
Lasers are becoming increasingly important in today's LED revolution and are essential for increasing the efficiency and
reducing manufacturing cost of LEDs. Excimer lasers provide unique homogeneous illumination of large areas, and are
ideally suited for laser lift off (LLO) of the LED film from the sapphire substrate used for epitaxial growth. In this paper
we will discuss the excimer laser lift off technique for manufacturing vertical type LEDs, and how it can be applied to
GaN and AlN based LEDs. On the other hand, diode pumped solid state lasers excel in scribing and cutting of a number
of materials relevant to the LED industry: sapphire, silicon, silicon carbide, III-nitrides (gallium nitride and aluminum
nitride), as well as III-V semiconductors (gallium arsenide, gallium phosphide). In this paper we will discuss some of the
recent laser scribing techniques and how adequate selection of laser parameters and beam delivery optics allows for a
high quality high throughput process.
Scribing with ultra-violet (UV) lasers has emerged as an alternative method of scribing semiconductor wafers for separation, particularly for thin silicon and germanium wafers, as well as other brittle compound semiconductor wafers materials such as GaP and GaAs.
Excimer lasers are the third major classification of industrial laser in use today (the first being CO2 lasers and the second being solid state lasers, such as YAG). Excimer lasers are used with far field mask image projection techniques, and as such are potentially inefficient due to UV photons being lost at the mask. Cost effective materials processing requires that the maximum amount of available UV photons are efficiently utilized. This paper outlines some of the latest excimer laser beam delivery techniques currently used for high volume micromachining and via drilling production applications. UV solid state lasers are increasing in average power and beam quality but are still limited to a few watts of average power. New mask illumination techniques can improve production throughputs by factors of 2X to >10X over conventional excimer mask projection processing. This paper discusses methods currently available applying the high average power of 50 to 100 watts available with increasing cost effectiveness.
Excimer lasers were commercialized in the late 1970's. The laser community thought that by the early 1980's these UV lasers would enjoy a fruitful industrial market position. CO2 and solid state lasers required almost two decades to be fully accepted as industrial machine while the excimer laser was expected to be a fast learner benefiting from the learning curve of its big brothers. In retrospect, early excimer lasers had a bad reputation for being complicated, expensive and frequently out of commission. By the late 1980's a few excimer laser manufacturers had engineered the problems to acceptable levels for successful pilot lines and small scale manufacturing to begin. At this time, the real industrial learning curves began as engineers worked to refine many subsystems and support technologies. Today, excimer lasers are being used as true industrial lasers. They have a bright future with numerous and diverse market opportunities. This paper is an overview of the technologies proven to be successful in adapting modern excimer lasers to successful full production situations.