This paper reports our recent results on a new method for controlling
the internal strain and Light emission in Si-Si1-xGex quantum dots (QD
) by coating a special SiNx layer with controlled built-in stress. It
was found that by changing the stress in the coating layer, a systemat
ic change of photoluminescence intensity and peak position has been ob
served. An optimum experimental regime was found where improved light
emission remains after the SiNx coating, This provides a general way o
f preparing a stable dielectric film suitable for and controlling the
internal strain in the QD diodes and other structures.