A method for manufacturing a silicon nanodot thin film having uniform
doping concentration without damage by placing a substrate on a stage
within a chamber. The method further including depositing a matrix thin
film based on the silicon by PECVD, while doping a light emitting
material such as Erbium on the matrix thin film deposited by sputtering
process at the same time. The silicon nanodot film obtained by the
present invention has an improved light emitting characteristic in long
distance communication frequency range of 1.54 .mu.m as well as visible
light range.