The present invention relates to obeticholic acid:or a pharmaceutically acceptable salt, solvate or amino acid conjugate thereof. The method includes forming a cavity in the lid wafer, aligning the lid wafer with the device wafer so that the cavity is located substantially above the feature, and removing material substantially uniformly from the bottom surface of the lid wafer, until an aperture is formed at the cavity, over the feature on the device wafer. Movement of the chair is monitored by a sleeved stem which moves in the same manner as a joystick plus rotational controller.