Micro-transfer printing of thin films

A source wafer for heterogeneous integration through micro-transfer printing for integrated photonics systems and/or integrated electronics systems, said source wafer comprising:

• a source substrate;
• a film;
• wherein said film comprises at least one device coupon delimited by a periphery, wherein said device coupon comprises one or more recesses extending through said device coupon;
• one or more designed breakable tethers at said periphery and configured to secure said device coupon to said film;
• a sacrificial layer between said source substrate and said film, wherein said sacrificial layer comprises a sacrificial recess below one or more said recesses;
• a support material filling at least some pairs of recesses and sacrificial recesses, thereby forming support structures for said device coupon in said device coupon and in said sacrificial layer;
• and wherein a distance from any point of said device coupon to an edge of a recess and a distance from any point of said device coupon to said periphery of said device coupon are smaller than ten times a collapsing length for said film, wherein said collapsing length is determined by the following method steps:
• providing said film on top of said sacrificial layer on top of a test substrate;
• defining a test device coupon in said film with a fixed predetermined width and extending over a predetermined length;
• etching said sacrificial layer away between said test device coupon and said test substrate, thereby suspending said test device coupon above said test substrate and forming a cavity extending between said test device coupon and said test substrate;
• and
• repeating said defining and said etching for different test device coupons of said fixed predetermined width and for increasing predetermined lengths for said test device coupons until a predetermined length for which a test device coupon first touches said test substrate along said fixed predetermined width, thereby determining said collapsing length.