<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The paper reports the design, fabrication and characterization of silicon-on-insulator (SOI) microring resonators using shallow etched rib waveguides. The variation of the <formula formulatype="inline"><tex Notation="TeX">$Q$</tex></formula>-factor of microring resonators as a function of the ring diameter and coupling gap between the input waveguide and the ring is studied. Such structures are fabricated using e-beam lithography and reactive ion etching steps. Propagation loss of shallow etching rib waveguide has been evaluated to 0.8 dB/cm for wavelengths around 1550 nm. With a ring diameter of 100 <formula formulatype="inline"> <tex Notation="TeX">$\mu{\rm m}$</tex></formula> and a coupling gap of 450 nm, the measured <formula formulatype="inline"><tex Notation="TeX">$Q$</tex> </formula>-factor is 35300. These results are matched by 3-D numerical optical modeling. </para>