Helium atom scattering (HAS) is a unique technique suitable for studying the structure and dynamics of the outermost layers of crystalline surfaces. In this report, we describe a very compact high-performance HAS apparatus developed for high resolution surface studies. Result of the helium atom scattering experiments on the single crystal copper surfaces under irradiation by H atoms are discussed. Application of helium atom scattering to the understanding of physical and chemical processes in fabrication of sub-quarter-micron Cu interconnects for ultra-large scale integration circuits is discussed.