Isolation structure for micro-transfer-printable devices

• US 10,297,502 B2
• Filed: 02/28/2017
• Issued: 05/21/2019
• Est. Priority Date: 12/19/2016
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA), X-FAB Semiconductor Foundries AG (X-FAB Silicon Foundries SE)
• Original Assignee: X-Celeprint Limited, X-FAB Semiconductor Foundries AG (X-FAB Silicon Foundries SE)
• Inventors: Bower, Christopher Andrew, Cok, Ronald S., Nevin, William Andrew, Kittler, Gabriel
• Primary Examiner(s): Luu, Chuong A
• Application Number:
  US15/445,728
• Publication Number:
  US 20180174910A1
• Time in Patent Office: 812 Days
• Field of Search: 257 88
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/76283 Lateral isolation by refilling of trenches with dielectric material
• CPC Class Codes: H01L 21/7806 involving the separation of the active layers from a substrate
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 2221/68318 Auxiliary support including means facilitating the separation of a device or wafer from the auxiliary support
• CPC Class Codes: H01L 2221/6835 used as a support during build up manufacturing of active devices
• CPC Class Codes: H01L 2221/68354 used to support diced chips prior to mounting
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H01L 2221/68381 Details of chemical or physical process used for separating the auxiliary support from a device or wafer
• CPC Class Codes: H01L 25/50 Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence

Abstract

A semiconductor structure suitable for micro-transfer printing includes a semiconductor substrate and a patterned insulation layer disposed on or over the semiconductor substrate. The insulation layer pattern forms one or more etch vias in contact with the semiconductor substrate. Each etch via is exposed. A semiconductor device is disposed on the patterned insulation layer and is surrounded by an isolation material in one or more isolation vias that are adjacent to the etch via. The etch via can be at least partially filled with a semiconductor material that is etchable with a common etchant as the semiconductor substrate. Alternatively, the etch via is empty and the semiconductor substrate is patterned to form a gap that separates at least a part of the semiconductor device from the semiconductor substrate and forms a tether physically connecting the semiconductor device to an anchor portion of the semiconductor substrate or the patterned insulation layer.

Claims

1. A semiconductor structure suitable for use in micro-transfer printing, comprising:

a semiconductor substrate;

a patterned insulation layer disposed on or over the semiconductor substrate, the patterned insulation layer comprising an insulation material and defining one or more etch vias extending through the patterned insulation layer and in contact with the semiconductor substrate; and

a semiconductor device disposed entirely on the patterned insulation layer, wherein at least a portion of the semiconductor device is surrounded by an isolation material in one or more isolation vias disposed on the patterned insulation layer, the one or more isolation vias are adjacent to and in contact with at least one of the one or more etch vias, and the patterned insulation layer is disposed at least partially between the semiconductor device and the semiconductor substrate,

wherein the semiconductor substrate and the semiconductor device comprise one or more semiconductor materials that are differentially etchable from the isolation material and from the insulation material, wherein the one or more etch vias are at least partially filled with one of the one or more semiconductor materials, and wherein the semiconductor device is electrically isolated from the semiconductor substrate.

2. The semiconductor structure of claim 1, wherein the patterned insulation layer and the isolation material comprise a same material.

3. The semiconductor structure of claim 1, wherein the semiconductor substrate and the semiconductor device comprise a same crystalline material.

4. The semiconductor structure of claim 1, comprising a plurality of isolation vias surrounding a corresponding plurality of semiconductor devices disposed on the patterned insulation layer, wherein each isolation via of the plurality of isolation vias is adjacent to and in contact with an etch via.

5. The semiconductor structure of claim 4, wherein the patterned insulation layer defines a corresponding unique etch via for each semiconductor device of the plurality of semiconductor devices such that a portion of the semiconductor substrate under each semiconductor device can be etched by an etchant provided through the corresponding unique via.

6. The semiconductor structure of claim 4, wherein the patterned insulation layer defines a common etch via corresponding to two or more semiconductor devices of the plurality of semiconductor devices such that a portion of the semiconductor substrate under each of the two or more semiconductor devices can be etched by an etchant provided through the common etch via.

7. The semiconductor structure of claim 1, wherein the one or more etch vias are at least partially filled with a semiconductor material that is etchable with a common etchant as the semiconductor substrate.

8. The semiconductor structure of claim 1, wherein (i) the semiconductor device is an integrated circuit, (ii) the semiconductor device is a light-emitting diode, (iii) the semiconductor device comprises a diode, (iv) the semiconductor device comprises a transistor, or any combination of (i), (ii), (iii), and (iv).

9. The semiconductor structure of claim 1, wherein the semiconductor device has at least one of a length and a width less than or equal to 1000 microns.

10. The semiconductor structure of claim 1, wherein the semiconductor device has a thickness less than or equal to fifty microns.

11. The semiconductor structure of claim 1, wherein the one or more tethers comprise a buried oxide layer in a silicon on insulator substrate.

12. The semiconductor structure of claim 1, wherein the insulation layer and the isolation material are at least one of a dielectric material, a silicon oxide and a silicon nitride.

13. The semiconductor structure of claim 1, wherein the semiconductor substrate and the semiconductor material are silicon, silicon <

1 1 1>

, or silicon <

1 0 0>

.