Walkman PLD

Fig. 1: Cross section of the chamber

The chamber is about 250 mm in diameter. The layout of the major components can be seen in the cross-section image (Fig. 1). The top flange holds the sample stage, which allows the sample to be freely rotated. The top flange also holds the heating laser optics and two mask manipulators. The masks can be used for combinatorial library or device processing. The most common use is to grow composition or thickness spread samples.

Fig. 2: Outside view of the chamber. The RHEED gun is on the left.

This system uses scanning-beam RHEED for film growth monitoring. The RHEED gun can be seen on the left side of the chamber in the outside view (Fig. 2).

The bottom of the chamber has a 4-target carousel for ablation targets. The whole target stage can be flipped to one side to give a clear view of the sample from the bottom viewport. This location is occupied by a camera, pyrometer, or some other optical measurement system.

This design has no sample height adjustment. The loading line is set for sample loading and a wobble stick is used to lift targets from the transfer rod to the target carousel.

Fig. 3: Inside view of the chamber, showing the sample stage.

Fig. 4: The top flange of the chamber.

The sample stage is in the center of the spherical chamber (Fig. 3). A sample holder slides into the stage from the side. The heating laser light enters the chamber from a viewport at the top and heats only the sample holder. All other components in the chamber remain at low temperature, reducing degassing.

The top flange can be seen more clearly in Fig. 4. The flange is standing on a support stand in the figure. The tubular sample stage is in the middle. The linear mask stages are visible close to the top. Mask holders extend to the left and hold mask plates, which are just below the sample.

Fig. 5: View of the chamber with the top flange removed.

In Fig. 5, the oxygen nozzle is visible on the right. The target carousel has been flipped to the left side to expose the bottom viewport. The target loading wobble stick is parked at the top/left corner.