The particle removal efficiency (PRE) of single-wafer substrates using dual-fluid spray-cleaning technology was investigated. The ratio displacement-diameter(H/D), which is dimensionless, is introduced to discuss the effect of PRE on a single-wafer surface. In addition, the effects of spray time and nozzle injection pressure on PRE are discussed. The results show that increasing the spray time and nozzle injection pressure can increase PRE. The highest PRE occurred when the displacement-diameter ratio was close to 1. When the ratio was less than 1, the PRE increased with an increase in the displacement–diameter ratio. When the ratio was greater than 1, the partial area of the wafer surface was not washed, and the PRE decreased rapidly with an increase in the ratio. The dual-fluid spray-cleaning method can achieve more than 99% PRE for particle sizes between 0.2 .m and 0.3 .m and more than 96% PRE for particle sizes between 0.1 m and 0.5 m.