The effective energy efficiency and the over filling factor of thin film ablation process with lasers of different beam shape

Abstract

Structuring and patterning of thin layer via selective laser ablation is one of the key technologies in production of display and photovoltaic. Concurrently, there are two ablation processes used in production of thin film solar: Scribing via selective ablation and edge isolation via deletion. Beside the wave length, the pulse length and the peak power, the beam profile of the laser is of essential importance for the efficiency of the ablation process and for the productivity. The most currently lasers of high beam quality have Gaussian beam profile with circular cross section. Because of threshold behaviour Gaussian beam profile is not favourable for ablation process. On the other side there are emerging laser concepts which deliver rectangular or square top-hat beams with high beam quality. In this paper we will discuss and compare ablation processes with circular Gaussian beams, one dimensional top-hat beams and two dimensional top-hat beams. The major concern will be the effective energy efficiency of the process and the over filling factor obtainable the different beam profiles.Structuring and patterning of thin layer via selective laser ablation is one of the key technologies in production of display and photovoltaic. Concurrently, there are two ablation processes used in production of thin film solar: Scribing via selective ablation and edge isolation via deletion. Beside the wave length, the pulse length and the peak power, the beam profile of the laser is of essential importance for the efficiency of the ablation process and for the productivity. The most currently lasers of high beam quality have Gaussian beam profile with circular cross section. Because of threshold behaviour Gaussian beam profile is not favourable for ablation process. On the other side there are emerging laser concepts which deliver rectangular or square top-hat beams with high beam quality. In this paper we will discuss and compare ablation processes with circular Gaussian beams, one dimensional top-hat beams and two dimensional top-hat beams. The major concern will be the effective energy efficiency of...