Product features:
1. The outer shell of the machine is treated with cold-rolled sheet paint, and the inner liner is made of stainless steel 316L material; The heater is evenly distributed around the outer wall of the inner container, and there are no electrical accessories or flammable or explosive devices inside the container. The tempered and bulletproof double-layer glass door provides a clear view of the objects inside the observation studio.
2. The tightness of the box door closure can be adjusted, and the silicone rubber door sealing ring formed as a whole ensures high vacuum inside the box.
3. Microcomputer intelligent temperature controller, with dual digital display for setting and measuring temperature and PID self-tuning function, precise and reliable temperature control.
4. The intelligent touch screen control system, paired with Mitsubishi PLC modules from Japan, allows users to change the program, temperature, vacuum degree, and duration of each program according to different process conditions.
5. HMDS gas sealed automatic suction and addition design, with excellent vacuum box sealing performance, ensures that HMDS gas has no concerns about leakage.
6. The entire system is made of materials, dust-free materials, and suitable for purifying environments in 100 level lithography rooms.
Optional accessories:
Vacuum pump: German brand, Leybold "DC" bipolar series rotary vane oil pump, with high ultimate vacuum, low noise, and stable operation.
Connecting pipe: Stainless steel corrugated pipe, fully sealed to connect the vacuum pump to the oven.
The necessity of HMDS preprocessing system:
In the semiconductor production process, photolithography is an important process link for integrated circuit pattern transfer, and the quality of coating directly affects the quality of photolithography. The coating process is also particularly important. In the process of photoresist coating, the vast majority of photoresist is hydrophobic, while the hydroxyl groups and residual water molecules on the surface of silicon wafers are hydrophilic. This results in poor adhesion between photoresist and silicon wafers, especially for positive photoresist. During development, the developer solution will invade the connection between photoresist and silicon wafers, which can easily cause floating stripes, floating photoresist, etc., leading to the failure of photoresist pattern transfer. At the same time, wet etching is prone to lateral corrosion. HMDS (hexamethyldisilazane), a viscosity enhancer, can effectively improve this situation. After coating HMDS onto the surface of silicon wafer, it can react to generate compounds mainly composed of siloxane by heating in an oven. It successfully transforms the surface of silicon wafers from hydrophilic to hydrophobic, and its hydrophobic groups can bond well with photoresist, acting as coupling agents.
The principle of HMDS vacuum oven:
The HMDS pretreatment system can uniformly coat a layer of HMDS on the surface of silicon wafers and substrates by adjusting parameters such as working temperature, treatment time, and holding time during the HMDS pretreatment process in the oven. This reduces the contact angle of the silicon wafers after HMDS treatment, lowers the amount of photoresist used, and improves the adhesion between photoresist and silicon wafers.
The general workflow of HMDS vacuum oven:
First, determine the operating temperature of the oven. A typical preprocessing procedure is to turn on the vacuum pump to evacuate, wait for the vacuum degree inside the chamber to reach a certain high vacuum degree, and then start filling nitrogen gas. After reaching a certain low vacuum degree, the process of vacuuming and filling nitrogen gas is carried out again. After reaching the set number of nitrogen gas filling times, it is held for a period of time to fully heat the silicon wafer and reduce the moisture on the surface of the silicon wafer. Then start vacuuming again and fill with HMDS gas. After reaching the set time, stop filling with HMDS solution and enter the holding phase to allow the silicon wafer to fully react with HMDS. After reaching the set holding time, start vacuuming again. Fill with nitrogen to complete the entire operation process. The reaction mechanism between HMDS and silicon wafer is shown in the figure: first heat to 100 ℃ -200 ℃ to remove the moisture on the surface of the silicon wafer, then HMDS reacts with the surface OH to generate silicon ether on the surface of the silicon wafer, eliminating hydrogen bonding and turning the polar surface into a non-polar surface. The entire reaction continues until steric hindrance (larger trimethylsilane groups) prevents further reaction.
Exhaust emissions, etc.: Excess HMDS steam (exhaust) will be extracted by a vacuum pump and discharged into a dedicated exhaust gas collection pipeline. Special treatment is required when there is no dedicated exhaust gas collection pipeline.
Cold rolled shell plate baked paint
