ClassOne Cuts Copper Plating Costs

New CopperMax system can reduce plating costs by over 95 percent

ClassOne Technology, manufacturer of ‘budget-friendly’ Solstice plating systems, has announced that its new CopperMax system is demonstrating major copper plating cost reductions for users of ≤200mm wafers.

“Like the rest of our equipment, this new chamber aims to serve all those smaller wafer users who have limited budgets,” said Witt. “Simply stated, CopperMax is going to give them a lot more copper plating performance for a lot less.”

ClassOne cited actual performance data from a CopperMax pilot installation on a Solstice tool at a Fortune 100 customer. Over a six-month period the customer tracked their actual production operating costs while using the new chamber for copper TSV, Damascene and high-rate copper plating. For the three processes with CopperMax they reported that operating costs were reduced between 95.8 percent and 98.4 percent compared with previously used conventional plating chambers.

“Many of our emerging market customers are starting to do copper plating,” said Kevin Witt, President of ClassOne Technology. “So we’ve spent a lot of time on the process, working to reduce customer costs and also increase performance. And the new CopperMax chamber is proving to do both.”

ClassOne pointed out that consumables are the largest cost factor in copper plating. Optimising copper plating generally requires the use of expensive organic additives – which are consumed very rapidly and need to be replenished frequently.

“We learned, however, that over 97 percent of those expensive additives were not being consumed by the actual plating process,” said Witt. “Most were being used up simply by contact with the anode throughout the process! So, we designed our new copper chamber specifically to keep additives away from the anode — and the results are pretty dramatic. Significant savings can be realized by high- and medium-volume users with high throughputs as well as by lower-volume and R&D users that have long idle times.”

The company explained that the CopperMax chamber employs a cation-exchange semipermeable membrane to divide the copper bath into two sections. The upper section contains all of the additives, and it actively plates the wafer. The lower section of the bath contains the anode that supplies elemental copper — which is able to travel through the membrane and into the upper section to ultimately plate the wafer. However, the membrane prevents additives from traveling down to the anode, where they would break down and form process-damaging waste products.

As a result, the CopperMax bath remains much cleaner, and bath life is extended by over 20x. This increases uptime, enables higher-quality, higher-rate Cu plating, and it reduces cost of ownership very substantially.

For example, a customer using a Solstice system with six CopperMax chambers and running TSV and high-rate copper plating will save over $300,000 per year just from additive use reductions.

In addition, the CopperMax also reduces Cu anode expenses. The chamber is designed to use inexpensive bulk anode pellets instead of solid machined Cu material, which cuts anode costs by over 50 percent. And since the pellets have 10x greater surface area they also increase the allowable plating rates.