In patterned sapphire substrate manufacturing, there are two popular processes that are being used my many semiconductor companies - the Dry and the Wet process. And because these processes differ in many ways, it is important to understand the difference between the two so that you can determine which between the two suits best to your unique needs. Consider the following:
Dry etching
- considered to be the most common method to etch sapphire substrate; very slow process with a low throughput rate;
- Etching a standard 2-inch wafer can take between 30 and 60 minutes;
- it does not scale effectively. As a wafer size increases, throughput of a dry etcher falls as fewer wafers fit inside the vacuum chamber. And because of that, more expensive plasma etching tools are needed to achieve the same throughput as achieved by smaller wafers;
- dry etching rates range between 50nm and 200nm in a minute (an estimate by some experts);
- dry etching is also known in producing bright and efficient LEDs; however, the process takes so slow and produces limited throughput.
Wet etching
- is known to provide dual advantages of being extremely fast and a lot cheaper than dry etching;
- the LEDs that are produced using wet etching process are not as efficient and effective as that of the dry etching process; however, it is very scalable.
- it provides a considerable cost saving than the dry etching;
- in wet etching, a polishing touch-up work is done on the wafers so that light extraction efficiency is increased.
Here are some equipment being used in etching sapphire:
The Accubath Xe-Series -- an etching bath equipment from Imtec Acculine, was designed with Sapphire etching in mind but we know there are other processes that will benefit from the increased chemical reactivity that higher temperatures provide (300C). Processes that were previously thought to be too slow due to temperature limitations may now be practical because of innovations like this.
Hitachi High-tech Silicon Etch System -- a dry etching that is based on an ECR(*1) plasma source, capable of generating a stable high density plasma at very low pressure.
CDE-80N Chemical Dry Etching Equipment -- used chemical dry etching process for thin film in a gaseous state semiconductor process. Damage-free etching process, through perfect separation of the etching unit and plasma generating unit, enables wide use in the damage removal process.
Each of the etching processes discussed above has its own advantages and disadvantages. But, just like any other processes, choose the one you think can improve your bottom-line -- net income.
Dry etching
- considered to be the most common method to etch sapphire substrate; very slow process with a low throughput rate;
- Etching a standard 2-inch wafer can take between 30 and 60 minutes;
- it does not scale effectively. As a wafer size increases, throughput of a dry etcher falls as fewer wafers fit inside the vacuum chamber. And because of that, more expensive plasma etching tools are needed to achieve the same throughput as achieved by smaller wafers;
- dry etching rates range between 50nm and 200nm in a minute (an estimate by some experts);
- dry etching is also known in producing bright and efficient LEDs; however, the process takes so slow and produces limited throughput.
Wet etching
- is known to provide dual advantages of being extremely fast and a lot cheaper than dry etching;
- the LEDs that are produced using wet etching process are not as efficient and effective as that of the dry etching process; however, it is very scalable.
- it provides a considerable cost saving than the dry etching;
- in wet etching, a polishing touch-up work is done on the wafers so that light extraction efficiency is increased.
Here are some equipment being used in etching sapphire:
The Accubath Xe-Series -- an etching bath equipment from Imtec Acculine, was designed with Sapphire etching in mind but we know there are other processes that will benefit from the increased chemical reactivity that higher temperatures provide (300C). Processes that were previously thought to be too slow due to temperature limitations may now be practical because of innovations like this.
Hitachi High-tech Silicon Etch System -- a dry etching that is based on an ECR(*1) plasma source, capable of generating a stable high density plasma at very low pressure.
CDE-80N Chemical Dry Etching Equipment -- used chemical dry etching process for thin film in a gaseous state semiconductor process. Damage-free etching process, through perfect separation of the etching unit and plasma generating unit, enables wide use in the damage removal process.
Each of the etching processes discussed above has its own advantages and disadvantages. But, just like any other processes, choose the one you think can improve your bottom-line -- net income.
About the Author:
Paul Drake writes various industry-related topics such as etching sapphire equipment. He uses his years of work experience in a high tech industry in writing useful resources. To learn more about wet etching process, visit Imtec Acculine official website.
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