A Load Port Module serves as the interface between a wafer transport system and a semiconductor process tool such as an etcher or deposition system. It facilitates the safe and ultra-clean transfer of wafers from cassettes stored in the transport system into the vacuum environment of the process chamber for semiconductor fabrication steps. Let's take a closer look at the key components and functions of this critical module.

Wafer Cassette Access

The front end of a loadlock in Load Port Module includes a cassette-loading station where standard 25mm wafer cassettes containing up to 25 wafers can be automatically loaded and unloaded. A robotic handler on the transport system sets the cassette into place and latches it securely. An environmentally sealed door then closes to maintain isolation of the cleanroom air from the vacuum system. Sensor inputs confirming cassette presence and door closure status are relayed to the process tool's control system.

Vacuum-Compatible Design

Since wafers must be transferred between the atmospheric cassette environment and high-vacuum process chambers, a Load Port Module needs vacuum-compatible construction. Chambers, bellows sections, and sealing joints are machined from non-outgassing stainless steel or aluminum alloys certified for ultra-high vacuum contact. Viton O-rings, metal gaskets, and precision actuators enable dependable closure and integrity testing of all interfaces down to vacuum pressures below 1x10^-7 Torr.

Wafer Transfer Mechanisms

Various transfer mechanisms are incorporated into load port designs depending on the specific process tool interface. Common configurations include a linear motor-driven blade that reaches into the cassette to pick wafers one at a time or a robotic arm capable of lifting an entire shelf of wafers simultaneously. Cameras and light sources aid alignment while sensors confirm contact and monitor for particles during extraction and placement into the loadlock chamber.

Get More Insights On This Topic: Load Port Module