Automated Nanoscale Absolute Accuracy Alignment System for Transfer Printing

Abstract

The heterogeneous integration of micro- and nanoscale devices with on-chip circuits and waveguide platforms is a key enabling technology, with wide-ranging applications in areas including telecommunications, quantum information processing, and sensing. Pick and place integration with absolute positional accuracy at the nanoscale has been previously demonstrated for single proof-of-principle devices. However, to enable scaling of this technology for realization of multielement systems or high throughput manufacturing, the integration process must be compatible with automation while retaining nanoscale accuracy. In this work, an automated transfer printing process is realized by using a simple optical microscope, computer vision, and high accuracy translational stage system. Automatic alignment using a cross-correlation image processing method demonstrates absolute positional accuracy of transfer with an average offset of <40 nm (3σ < 390 nm) for serial device integration of both thin film silicon membranes and single nanowire devices. Parallel transfer of devices across a 2 × 2 mm 2 area is demonstrated with an average offset of <30 nm (3σ < 705 nm). Rotational accuracy better than 45 mrad is achieved for all device variants. Devices can be selected and placed with high accuracy on a target substrate, both from lithographically defined positions on their native substrate or from a randomly distributed population. These demonstrations pave the way for future scalable manufacturing of heterogeneously integrated chip systems.

Sub-micron-accuracy automated position and rotation registration method for transferred devices

“…This was achieved with an adequately sized matrix (correlator), that has the same dimensions as the devices to be detected. The cross-correlation method is similar to that presented in our previous work on spatial registration for high accuracy transfer printing [4] and is carried out with respect to x,y and θz variations. Figure 2 shows a schematic of the figures of merit being targeted on a uniform array.…”

“…Mass transfer is one of the main stages in the manufacturing of these hybrid optoelectronic devices and has many technological challenges, including the transfer yield and the realization of a precise inspection method [2], [3]. A key issue in this process is to rapidly assess the relative position of thousands of devices with accuracy in the 100nm range [4]. Furthermore, this measurement must be done rapidly, and with relatively simple imaging equipment, to allow it to be integrated into the manufacturing process.…”

Advanced transfer printing with in-situ optical monitoring for the integration of micron-scale devices

“…Furthermore, the microscope head used to image through the stamp is mounted on a movable rail that can be locked into position for a consistent field-of-view (FOV) position during printing. Automated control of the alignment process for donor and receiver chips and development of a fully integrated software control system for device alignment and printing stages has improved full process times from ≈ 30 mins in earlier systems [23]to only a few minutes for the full setup, alignment and print process.…”

Growth of type I superlattice III-V heterostructure in horizontal nanowires enclosed in a silicon oxide template

“…The most mature integration routes for III-V semiconductor material on Si substrate involve the transfer of the grown crystal from a lattice matched substrate onto Si. Already employed in industry, these integration routes bypass the issue of lattice mismatch between III and V and Si but become difficult to implement at 8 ′ ' wafer sizes [5][6][7]. Conversely, any monolithic route involving the direct growth of III-V semiconductor material on Si has to contend with lattice mismatch between the Si substrate and the epitaxially grown III-V layer as a source of defects [8].…”