Dicing of gallium–arsenide high performance laser diodes for industrial applications: Part II. Cleavage operation
✍ Scribed by K. Wasmer; C. Ballif; C. Pouvreau; D. Schulz; J. Michler
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 891 KB
- Volume
- 198
- Category
- Article
- ISSN
- 0924-0136
No coin nor oath required. For personal study only.
✦ Synopsis
Dicing of III-V based high-power laser diodes is commonly carried out in two steps. To start with, an initial defect is created in the devices by scratching it with a sharp diamond tip to allow a subsequent cleavage operation. Micro-scratching and cleavage are crucial operations for maximizing the yield production. Thus, this contribution is divided into two papers according to these essential operations.
The cleavage operation is the focus of this study for three material conditions based on gallium-arsenide (GaAs) previously scratched by a diamond tip (Berkovich). Due to its complexity, the cleavage operation was investigated through (a) finite element calculation, (b) the stress intensity factor K and (c) the cleavage operation itself. It can be demonstrated that a crack significantly diminishes the influence of loading condition. Additionally, three cleavage behaviors were observed depending on the initial conditions. First, the crack deviates from its path. This was observed when the shear stress component becomes more important than the tensile stress. Second, features are visible on the cleaved surface. This is generally the case when the median crack is small resulting in an unstable crack growth leading to catastrophic failure. Finally, perfectly atomic flat cleaved surfaces are produced. This is the case with larger median crack when, after unstable initiation, crack propagation is controlled.
The analyzes and results of the scratching operation completed in this contribution are