Measuring the growth parameters of Ge quantum dots(QDs) embedded in SiO_2/Si hetero-structure is prerequisite for developing the optoelectronic devices such as photovoltaics and sensors. Their optical properties can be tuned by tailoring the growth morphology and structures, where the growth parameters’ optimizations still need to be explored. We determine the effect of annealing temperature on surface morphology, structures and optical properties of Ge/SiO_2/Si hetero-structure. Samples are grown via rf magnetron sputtering and subsequent characterizations are made using imaging and spectroscopic techniques. Measuring the growth parameters of Ge quantum dots (QDs) embedded in SiO 2 / Si hetero-structure is prerequisite for developing the optoelectronic devices such as photovoltaics and sensors. Their optical properties can be tuned by tailoring the growth morphology and structures, where the growth parameters ’optimizations still need to be explored. We determine the effect of annealing temperature on surface morphology, structures and optical properties of Ge / SiO_2 / Si hetero-structure. Samples are grown via rf magnetron sputtering and subsequent characterizations are made using imaging and spectroscopic techniques .