The advantages of wet cleaning equipment and single-chip cleaning machine

 Moore's Law continues to accept new challenges, and wet etching cleaning equipment is also improving. Existing wet cleaning equipment can be divided into batch cleaning equipment (Bench Clean) according to the cleaning method, as shown in Figure 1 (a), and single piece cleaning equipment (Single Wafer Clean), as shown in Figure 1 (b).

Figure 1  Wafer wet cleaning diagram

The production process of a chip particles goes through thousands of processes, nanometers with the narrowing of the series, the number of processes is still increasing, so if the size of the wafer is larger, more chip particles can often be obtained through the same process, so the wafer size is from 6 in to 8 in to 12 in.

Under the premise of constant thickness, the disadvantage of larger wafer size is easier to break, and it is more difficult to control the uniformity of etching cleaning (Uniformity, U%).For Bench machine, the impact of fragmentation is fatal, and the crushing of single wafer may lead to the scrapping of the whole batch of 50 wafers. With the progress of technology, the single wafer washer can adjust the position of nozzle and chuck speed, and spray chemical liquid at different positions on the wafer surface to achieve better etching cleaning uniformity.

The biggest disadvantage of single-chip cleaning equipment is the production rate (Through Put) is low, but with the increase of equipment process chamber, the production rate of 4 cavity 8 cavity 12 cavity 24 cavity, the single wet cleaning machine has been basically equal to or even surpassed the Bench machine, so the future single wet cleaning machine must be the mainstream of cleaning equipment.

Single wafer clean Process chamber schematic as shown in Figure 1 (c), wafer cartridge (Wafer the chuck) holds and rotates the wafer to etch the wafer through a chemical solution.