Improvement of thickness uniformity and elements distribution homogeneity for multicomponent films p

• 作 者: 胡居广 李启文 林晓东 刘毅 龙井华 王刘杨 汤华斌
• 机 构: College of Physics Science and Technology, Shenzhen University,
• 出 处: Chinese Optics Letters
• 发表日期: 2014年07期
• 关键词: uniformity CIGS mirror deflection rotating eliminated scanned thick exceeding ar

In conventional pulsed laser deposition(PLD) technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uniform thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam,the laser’s focus is scanned across the rotating target surface. This arrangement maintains a constant reflectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated.This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.

In conventional pulsed laser deposition (PLD) technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing the uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products . We present a novel method based on PLD for depositing large CIGS films with uniform thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser’s focus is scanned across the rotating target surface. This arrangement maintains a constant reflectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated.This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness even exceeding ± 3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.