Coupon wafer and method of preparation thereof

A coupon wafer comprising a device coupon for use in a micro-transfer printing process used to fabricate an optoelectronic device,

• wherein the coupon wafer includes a wafer substrate, and the device coupon is attached to the wafer substrate via a tether;
• and
• wherein the tether comprises a dielectric material,
• wherein the wafer substrate defines a raised platform, below the device coupon, and has a channel adjacent to the raised platform,
• wherein the tether comprises:
• a first portion extending laterally along a top surface of the device coupon;
• a second portion extending from the first portion and vertically along a side surface of the device coupon;
• a third portion extending from the second portion and laterally away from a bottom of the device coupon;
• a fourth portion extending from the third portion and vertically along a side surface of the raised platform;
• and
• a fifth portion extending from the fourth portion and laterally along a floor of the channel,
• wherein the tether is a multi-layered tether comprising at least one of a layer of silicon nitride or a layer of silicon oxide,
• wherein the tether has a thickness of at least 20 nm and no more than 500 nm,
• wherein the tether includes a plurality of apertures therethrough, and
• wherein a gap is defined directly between a top surface of the raised platform and the device coupon, and directly between the top surface of the raised platform and the third portion of the tether.