Multi-Layer Photo Definable Glass with Integrated Devices

Abstract

The invention relates to eliminating or dramatically reducing the mechanical distortion induced in photo-definable glass as a function of temperature and time processing during metallization that enable multi-layer and single layer photo-definable structures, that can contain electronic, photonic, or MEMS devices to create unique vertically integrated device or system level structures.

Claims

1. A method for producing a fully dense metallized glass substrate where the metal is preferentially heated and or densified relative to the glass substrate comprising: depositing a metal paste on the single or a multi-layer glass structure; conducting a metallization thermal cycle with a thermal ramp rate of 10 C./min from 25 C. to 600 C., a 10 min hold at 600 C.; and ramp down from 600 C. to 25 C.; and annealing the metal to the single or a multi-layer photo-definable glass structure under nitrogen to prevent oxidation of the metal, wherein the metallization thermal cycle induces a permanent random physical distortion and optical transmission change in the glass structure; wherein: (a) a change in a position of the metal, the single or a multi-layer photo-definable glass structure, and one or more device structures after the metallization thermal cycle is less than 20 m; and (b) wherein a color of the glass substrate is not shifted greater than 75 nm, and (c) wherein a temperature to time ratio does not exceed 70 C./min.

2. The method of claim 1, wherein the metal is copper, silver, platinum, gold, or a combination thereof.

3. The method of claim 1, wherein the glass is photo-definable.

4. The method of claim 1, wherein the glass substrate contains electronic, photonic, or MEMS devices.

5. A method of integrating two or more glass substrates where the metal structures are preferentially heated and or densified relative to the glass substrate inducing change in the position of structures of less than 20 m and without significantly altering the color of the glass substrate, wherein a change in a position of structures of less than 20 m and wherein a color of the glass substrate is not shifted greater than 75 nm, and wherein a temperature time ratio of does not exceed 70 C./min, by a method comprising: depositing a metal paste on the single or a multi-layer glass structure; conducting a metallization thermal cycle with a thermal ramp rate of 10 C./min from 25 C. to 600 C., a 10 min hold at 600 C.; and ramp down from 600 C. to 25 C.; and annealing the metal to the single or a multi-layer photo-definable glass structure under nitrogen to prevent oxidation of the metal, wherein the metallization thermal cycle induces a permanent random physical distortion and optical transmission change in the glass structure.

6. The method of claim 5, wherein the metal is copper, silver, platinum, gold, or a combination thereof.

7. The method of claim 5, wherein the glass is photo-definable.

8. The method of claim 5, wherein the glass substrate contains electronic, photonic, or MEMS devices.

9. The method of claim 5, wherein the metals may reside partially through, fully through, in between, or on top of the glass-ceramic material, or a combination thereof.

10. A method for producing a single or a multi-layer glass structure with one or more devices on each of one or more layers with metal paste metallization comprising: depositing a metal paste on the single or a multi-layer photo-definable glass structure; conducting a metallization thermal cycle with a thermal ramp rate of 10 C./min from 25 C. to 600 C., a 10 min hold at 600 C.; and ramp down from 600 C. to 25 C.; and annealing the metal to the single or a multi-layer photo-definable glass structure under nitrogen to prevent oxidation of the metal, wherein the metallization thermal cycle induces a permanent random physical distortion and optical transmission change in the photo-definable glass structure.

11. The method of claim 5, wherein the metal is copper, silver, platinum, gold, or a combination thereof.

12. The method of claim 10, wherein the metal is copper, silver, platinum, gold, or a combination thereof.

13. The method of claim 10, wherein the glass is photo-definable.

14. The method of claim 10, wherein the glass substrate contains electronic, photonic, or MEMS devices.

15. The method of claim 10, wherein metallization thermal cycle at least one of: (1) constrains a change in the relative change in position of the metal, the glass, and the one or more device structures to less than 20 m, (2) wherein a color of the glass substrate is not shifted greater than 75 nm, or (3) wherein a temperature to time ratio does not exceed 70 C./min.

Description

DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures and in which:

[0013] FIG. 1 shows a graph of the absorption spectra for copper.

[0014] FIGS. 2A and 2B show a graph of the absorption spectra for APEX glass.

[0015] FIG. 3 shows a graph of the optical spectra for APEX glass after different thermal cycling and UV exposure.

[0016] FIG. 4 shows a graph of the temperature cycle for a silicon substrate for a rapid thermal annealing source. FIG. 5 shows a graph of the optical spectra for a rapid thermal annealing source.

DESCRIPTION OF EMBODIMENTS

[0017] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not restrict the scope of the invention.

[0018] FIG. 1 shows a graph of the absorption spectra for copper. FIGS. 2A and 2B show a graph of the absorption spectra for APEX glass. FIG. 3 shows a graph of the optical spectra for APEX glass after different thermal cycling and UV exposure. FIG. 4 shows a graph of the temperature cycle for a silicon substrate for a rapid thermal annealing source. FIG. 5 shows a graph of the optical spectra for a rapid thermal annealing source.

[0019] A source of the electromagnetic spectrum that is absorbed by metals and is nominally transparent to a photo-definable glass enables the heating, melting and densification of the metal deposited from a paste deposition process on a traditional glass or photo definable glass substrate is preferably a high intensity tungsten filament lamp. High intensity tungsten filament lamps are the heating source used in rapid thermal annealing (RTA) or rapid thermal processing (RTP). The time at temperature is such that it does not change the position of the features on the substrate by greater 20 m and the color shift of the glass is less than 75 nm. Experiments have shown that the time needs to be less than 10 min at 700 C. or a temperature time ratio of less than 70 C./min RTA is a process used in semiconductor device fabrication that consists of preferentially heating a single metal on a glass substrate or a stack of glass substrates.

[0020] Traditional RTA process can be performed by using either lamp based heating, a hot chuck, or a hot plate that a substrate. A hot chuck or a hot plate RTA will heat the substrate in addition to glass substrate. Lamp based heating RTA processes will heat the metal significantly more than the surrounding glass substrate allowing the metal to be heat-densified without inducing the permanent mechanical distortion or optical change in the glass substrate.

[0021] The electromagnetic spectrum that can achieve melting and densification of copper paste on a glass substrate includes but not limited to microwave frequency, visible, near infra-red and mid infra-red spectrum that can be generated by an inductive, microwave, or high intensity lamp.

[0022] To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as a, an and the are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims.

[0023] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.