Package structure including a cavity coupled to an injection gas channel composed of a permeable material

1. A packaging structure comprising:

a cap secured to at least one first substrate and forming at least one cavity between the cap and the first substrate;

a layer of at least one first material permeable to a gas, arranged in the cap and/or in the first substrate and/or at an interface between the cap and the first substrate, and forming at least one part of a wall of the cavity;

a portion of at least one second material non-permeable to said gas, the thickness of which is higher than or equal to that of the layer of the first material, and surrounding at least one first part of the layer of the first material forming said part of the wall of the cavity; and

an aperture passing through the cap or the first substrate and opening onto or into said part of the layer of the first material.

2. The packaging structure according to claim 1 , wherein said part of the layer of the first material surrounds the cavity.

3. The packaging structure according to claim 1 , further including at least one micro-device arranged in the cavity.

4. The packaging structure according to claim 1 , wherein the second material is a metal.

5. The packaging structure according to claim 1 , wherein the first material includes at least one of the following elements: semiconductor oxide, semiconductor nitride, and glass.

6. The packaging structure according to claim 1 , wherein at least one part of the portion of the second material is surrounded by a second part of the layer of the first material.

7. The packaging structure according to claim 1 , wherein the cap includes at least one second substrate.

8. The packaging structure according to claim 7 , wherein the layer of the first material and the portion of the second material are arranged at an interface between the first substrate and the second substrate.

9. The packaging structure according to claim 1 , wherein the layer of the first material is arranged between a support layer of the first substrate and an upper layer of the first substrate.

10. The packaging structure according to claim 3 , wherein the layer of the first material is arranged between a support layer of the first substrate and an upper layer of the first substrate, wherein the upper layer of the first substrate is a semiconductor layer in which the micro-device is made.

11. The packaging structure according to claim 10 , wherein the second material corresponds to a semiconductor similar to that of the upper layer of the first substrate.

12. The packaging structure according to claim 1 , wherein the first substrate is of an SOI-type and the layer of the first material corresponds to the insulating layer of the first substrate.

13. The packaging structure according to claim 1 , further comprising at least one plugging material arranged on and/or in the aperture such that the cavity is hermetically closed.

14. The packaging structure according to claim 13 , wherein the aperture passes through said part of the layer of the first material and opens onto a portion of electrically conducting material, and the plugging material corresponds to an electrically conducting layer arranged at least in the aperture and electrically connecting the portion of the electrically conducting material to an electrical contact arranged outside the aperture.

15. The packaging structure according to claim 1 , further comprising several cavities formed between the cap and the first substrate and arranged adjacent to each other, wherein at least one dimension of each of the parts of the layer of the first material forming the parts of the wall of at least two of the cavities is different for each of said at least two of said cavities and/or wherein a dimension of a cross-section of the aperture associated with each of at least two of the cavities is different.

16. The packaging structure according to claim 15 , wherein the portions of the second material surrounding each of the parts of the layer of the first material forming the part of the wall of each of the cavities are distinct from each other.

17. A method for manufacturing a packaging structure, the method comprising:

making at least one cap and at least one first substrate for being secured to each other by forming at least one cavity between the cap and the first substrate;

making a layer of at least one first material permeable to at least one gas, arranged in the cap and/or in the first substrate and/or at an interface between the cap and the first substrate, and for forming at least one part of a wall of the cavity;

making at least one portion of at least one second material non-permeable to said gas, the thickness of which is higher than or equal to that of the layer of the first material, and surrounding at least one first part of the layer of the first material for forming said part of the wall of the cavity;

securing the cap to the first substrate, forming the cavity; and

making at least one aperture passing through the cap or the first substrate and opening onto or into said part of the layer of the first material.

18. The manufacturing method according to claim 17 , further comprising, after the making of the aperture, injecting said gas into the cavity through the aperture and said part of the layer of the first material, and then hermetically closing the cavity by forming at least one plugging material on and/or in the aperture.