The effects of the capillary stresses during the drying of p+ -type porous silicon (PS) layers are reported. The cracking of the PS layers occurs for samples thicker than a critical thickness value hc. Taking into account the elastic properties of p + -type PS material, a simple model shows that hc varies as (1 - p)3 and 1/γ2LV, where p is the porosity and γLV is the surface tension of the drying liquid. A good agreement with experimental results is observed. This study leads also to a very easy and simple method which increases the hc value by a factor of about 25 when using pentane as the drying liquid (instead of water).
- Elastic properties
- Growth mechanism