Fig. 1. Structure of VCSEL epitaxial structure

Fig. 2. Oxidation rate versus temperature (inset is SEM picture of oxidized sample section at 435 ℃)

Fig. 3. Oxidation depth versus time

Fig. 4. Oxide pores at different oxidation temperatures. (a) 400 ℃; (b) 420 ℃; (c) 435 ℃

Fig. 5. Problems generated after sample oxidation. (a) Delamination fracture; (b) longitudinal shrinkage

Fig. 6. Typical and optimized temperature control curves

Fig. 7. SEM photographs of oxidized samples under different temperature control conditions. (a) Typical temperature control process; (b) optimized temperature control process