Ultra-high-Q optical resonators have played an important role over a wide range of research fields including nonlinear optics, cavity optomechanics, quantum information and optical telecommunications. We demonstrate a new resonator on a silicon chip with a record Q factor of 875 million, surpassing even micro-toroids. This on-chip resonator is fabricated based on the standard semiconductor process without anomalous process such as silica reflow, which was essential for micro-toroids, thereby expanding the range of integration opportunities and possible applications. The techniques developed for ultra-smooth dielectric surface of the optical resonator to achieve high-Q property was used to enhance the performance of optical waveguide on a chip which lags far behind that of optical fiber, featuring attenuation rates many orders larger. We demonstrate monolithic waveguide as long as 27 meters with attenuation rates below 0.1 dB/m over optical telecommunication band.