Lithium microbattery fabrication method

Patent metadata

Field	Value
Publication number	US-9373864-B2
Application number	US-201414445874-A
Country	US
Kind code	B2
Filing date	Jul 29, 2014
Priority date	Jul 29, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

The method for fabricating a lithium microbattery is performed from a stack of layers successively including: a first layer made from a first material, a second layer made from a second material, a solid electrolyte layer and a first electrode. The method further includes etching to form a first pattern made from the first material and a second pattern made from the second material, the second pattern defining a covered area and an uncovered area of the electrolyte layer. The uncovered area is then etched using the second pattern as etching mask. After etching of the first pattern, a lithium-based layer is formed on the second pattern, the lithium-based layer and the second pattern forming a second lithium-based electrode.

First claim

The invention claimed is:

1. A fabrication method of a lithium microbattery, comprising the following successive steps:
providing a stack of layers successively comprising:
a first layer made from a first material;
a second layer made from a second material configured to combine with lithium atoms;
a solid electrolyte layer;
a first electrode;

etching the first and second materials to form a first pattern made from the first material and a second pattern made from the second material, the second pattern defining an uncovered area and a covered area of the electrolyte layer;
etching the uncovered area of the electrolyte layer using the second pattern as etching mask, and eliminating the first pattern;
depositing in localized manner a lithium-based layer on the second pattern, the second material being configured such that the lithium atoms diffuse into the second pattern, the lithium-based layer and the second pattern forming a lithium-based second electrode.

2. The method according to claim 1 , wherein the formation of the first and second patterns comprises the following steps:
etching the first material so as to define the first pattern made from the first material arranged on the second layer;
etching the second material to form the second pattern using the first pattern as etching mask.

3. The method according to claim 1 , wherein the etching of the uncovered area of the electrolyte layer and etching of the first pattern are performed simultaneously.

4. The method according to claim 1 , wherein formation of the second pattern is achieved by plasma etching of the second material using the electrolyte layer as etch stop layer.

5. The method according to claim 1 , wherein the lithium-based layer and the second material of the second pattern undergo heat treatment configured to make the lithium atoms diffuse into the second pattern.

6. The method according to claim 1 , wherein the second electrode comprises a lithium atom concentration of at least 90%.

7. The method according to claim 1 , wherein the electrolyte layer is formed by a material selected from the group consisting of LiPON, LiSiPON, Thio-LiSiCON, and LiBON.

8. The method according to claim 1 , wherein the second layer is formed by a material selected from the group consisting of Si, Ge, Sn, C, Au, and Pt.

9. The method according to claim 1 , wherein the first layer is formed by a material selected from the group consisting of Al, Al 2 O 3 , Ti, Ni, Cr, and LiPON.

10. The method according to claim 1 , wherein the first pattern is formed by deposition of a photoresist layer on the first layer followed by a photolithography step and an etching step of the first material.

11. A fabrication method of a lithium microbattery, comprising the following successive steps:
providing a stack of layers successively comprising:
a first layer made from a first material;
a second layer made from a second material configured to combine with lithium atoms;
a solid electrolyte layer;
a first electrode;

etching the first and second materials to form a first pattern made from the first material and a second pattern made from the second material, the second pattern defining an uncovered area and a covered area of the electrolyte layer;
etching the uncovered area of the electrolyte layer using the second pattern as etching mask, and eliminating the first pattern;
depositing in localized manner a lithium-based layer directly on an uncovered area of the second pattern, the second material being configured such that the lithium atoms diffuse into the second pattern, the lithium-based layer and the second pattern forming a lithium-based second electrode.

Assignees

• Commissariat À L En Atomique Et Aux En Alternatives
• Commissariat Energie Atomique

Inventors

• Oukassi Sami
• Bazin Arnaud

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M10/0585 Primary

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• B81C1/00396

  Mask characterised by its composition, e.g. multilayer masks · CPC title

• H01M10/38

  Construction or manufacture · CPC title

• H01M4/0421

  involving vapour deposition · CPC title