High capacity compact lithium thin film battery

Abstract

A method of forming a thin film battery may include: forming a groove in a substrate; depositing a template on a top surface of the substrate, wherein the template is aligned with the groove; depositing a cathode layer in the groove, wherein the cathode layer is in direct contact with the template; and compressing the cathode layer into the groove to reduce the thickness of the cathode layer. Compressing the cathode layer into the groove may include applying isostatic pressure to the cathode layer using a press head. The method may also include depositing an electrolyte layer on top of the cathode layer, depositing an anode layer on top of the electrolyte layer, and depositing an anode current collector layer on top of the anode layer.

Description

Technical Field

[0001] The present invention relates generally to thin film batteries and, more particularly, to methods and structures for forming high capacity compact lithium thin film batteries. Background Art

[0002] A typical thin film lithium battery includes different material layers, including but not limited to cathode, separator and anode. The capacity of such a battery is usually limited by the thickness and structure of the cathode layer. Therefore, a thick cathode layer can be converted into a battery with high capacity, while a thin cathode layer can be converted into a battery with low capacity. In addition, these layers are deposited using thin film vacuum deposition techniques, such as sputtering or plasma enhanced chemical vapor deposition. Summary of the invention

[0003] According to one embodiment of the present invention, a method for forming a thin film battery is provided. The method may include forming a groove in a substrate, depositing a template on the top surface of the substrate, wherein the template is aligned with the groove, depositing a cathode layer in the groove, wherein the cathode layer is in direct contact with the template, and compressing the cathode layer into the groove to reduce the thickness of the cathode layer. Compressing the cathode layer into the groove may include using a pressure head to apply isostatic pressure to the cathode layer. The template may be made of a high temperature polymer or a low temperature polymer. The method may include depositing a cathode collector layer along the sidewalls and bottom of the groove, depositing a cathode layer in the groove, and compressing the cathode layer into the groove to reduce the thickness of the cathode layer. The method may also include depositing an electrolyte layer on top of the cathode layer, depositing an anode layer on top of the electrolyte layer, and depositing an anode collector layer on top of the anode layer.

[0004] According to another embodiment of the present invention, a method for forming a plurality of thin film batteries is provided. The method may include forming a plurality of grooves in a substrate, forming a plurality of cutting channels in the substrate, wherein each of the plurality of cutting channels is located between each of the plurality of grooves, depositing a template on a top surface of the substrate, wherein the template is aligned with the grooves, depositing a cathode layer in the plurality of grooves, wherein the cathode layer is in direct contact with the template, and compressing the cathode layer into the plurality of grooves to reduce the thickness of the cathode layer.

[0005] According to another embodiment of the present invention, a structure is provided. The structure may include a cathode current collector layer disposed along a substrate and a cathode layer buried in the substrate, wherein the top surface of the cathode layer is substantially flush with the top surface of the cathode current collector layer. The structure may include an anode layer located on top of an electrolyte layer, an anode current collector layer located on top of the anode layer, and an insulator layer located on top of the anode current collector layer, wherein the electrolyte layer separates the cathode layer from the anode layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The following detailed description, which is given by way of example and is not intended to limit the invention thereto, will be best understood in conjunction with the accompanying drawings, in which:

[0007] Figure 1 is a cross-sectional view showing a trench created in a substrate according to an exemplary embodiment;

[0008] Figure 2 is a cross-sectional view showing a deposition cathode according to an exemplary embodiment;

[0009] Figure 3 is a cross-sectional view showing an aligned indenter on top of a cathode according to an exemplary embodiment;

[0010] Figure 4 is a cross-sectional view showing a polished cathode layer according to an exemplary embodiment;

[0011] Figure 5 is a cross-sectional view showing deposition of an additional layer on top of a polished cathode layer according to an exemplary embodiment;

[0012] Figure 6 is a cross-sectional view showing a cap on top of a deposited layer according to an exemplary embodiment

[0013] Figure 7 is a cross-sectional view showing a plurality of batteries according to an exemplary embodiment; and

[0014] Fig. 8A and 8B is a cross-sectional view illustrating a plurality of batteries on a substrate according to an exemplary embodiment.

[0015] The drawings are not necessarily to scale. The drawings are merely schematic representations and are not intended to depict specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention. In the drawings, the same reference numerals represent the same elements. DETAILED DESCRIPTION

[0016] Detailed embodiments of the claimed structures and methods are disclosed herein; however, it is understood that the disclosed embodiments are merely illustrative of the claimed structures and methods that may be implemented in various forms. However, the present invention may be implemented in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to make this disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art. In the description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments.

[0017] For the purposes of the following description, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom" and their derivatives shall refer to the disclosed structures and methods as oriented in the accompanying drawings. The terms "overlying", "on top", "located at" or "located on top" indicate that a first element, such as a first structure, is present on a second element, such as a second structure, wherein an intermediate element, such as an interface structure, may be present between the first element and the second element. The term "direct contact" means that a first element (e.g., a first structure) and a second element (e.g., a second structure) are connected without any intermediate conductive, insulating or semiconducting layer at the interface of the two elements.

[0018] In order not to obscure the presentation of embodiments of the present invention, in the following detailed description, some processing steps or operations known in the art may be combined together for presentation and for illustration purposes, and may not be described in detail in some instances. In other cases, some processing steps or operations known in the art may not be described at all. It should be understood that the following description is more focused on the distinguishing features or elements of various embodiments of the present invention.

[0019] Embodiments of the present invention generally relate to a high capacity compact lithium thin film battery, and more particularly, to a structure and method for forming a high capacity lithium thin film battery with a small sealed surface area.

[0020] Typically, thin film lithium batteries are made of different materials, each of which is stacked on top of each other. Such layers may include, but are not limited to, a cathode collector layer, a cathode layer, an electrolyte layer, an anode layer, an anode collector layer, and an insulating layer. In addition, the capacity of conventional thin film lithium batteries is generally limited by the thickness and structure of the cathode layer. Therefore, a thick cathode layer can be converted into a battery with a high capacity, while a thin cathode layer can be converted into a battery with a low capacity.

[0021] Typically, these layers are deposited using different vacuum deposition techniques, such as sputtering. However, these vacuum deposition techniques are limited by their deposition rates. Therefore, it is time-consuming and expensive to use sputtering deposition techniques to manufacture thin-film lithium batteries. This is even more time-consuming and expensive when producing high-capacity batteries, because such batteries require thick cathode layers, which means that longer sputtering times are required to deposit such thick cathodes. In addition, since lithium is highly reactive, such batteries require large seals to protect the lithium layer from contaminants such as water or oxygen. As a result, the batteries produced are also physically large, with a surface area between 10mm2 and 1000mm2, where the surface area of ​​the seal itself is at least 1mm2.

[0022] As technology advances, emerging IoT sensors and smart devices may require batteries with a surface area of ​​less than 10 mm2 to power these sensors and smart devices. Therefore, it is necessary to develop a thin film lithium battery with high capacity and a total surface area of ​​less than 10 mm2, preferably about 1 mm2, including sealing. In addition, it is necessary to reduce processing costs to a level far below that achievable using current thin film technology. Therefore, embodiments of the present invention provide a structure and method for producing a high capacity battery having a total surface area of ​​less than 10 mm2 while reducing processing time and cost.

[0023] Reference now Figure 1 , shows a structure 100 according to an embodiment. The structure 100 may include a substrate 102, a cathode current collector layer 104, a template 106, and a trench 108. The substrate 102 may include a silicon-based material. Illustrative examples of silicon-based materials suitable for the substrate 102 may include, but are not limited to, silicon, silicon germanium carbon, silicon carbon, and multilayers thereof. In an embodiment, the substrate 102 may be degenerate doped silicon that allows for back electrode contact.

[0024] The substrate 102 may be patterned using known photolithography techniques to produce the trenches 108. The substrate 102 may also be etched to produce the trenches 108. For example, reactive ion etching may be used to etch the trenches 108 in the substrate 102. Once the trenches 108 are formed, the cathode current collector layer 104 is conformally deposited on the top surface of the substrate 102 and along the sidewalls and bottom of the trenches 108. The cathode current collector layer 104 may be deposited using various deposition processes, such as evaporation, chemical vapor deposition, atomic layer deposition, sputtering, or other suitable deposition processes.

[0025] The cathode current collector layer 104 can be made of an inactive metal, such as copper, silver, gold, platinum, or any other suitable inactive metal. The cathode current collector layer 104 is conductive and acts as a barrier layer. In addition to providing a current path to the cathode (110), the cathode current collector layer 104 can also prevent impurities found in the substrate 102 and the environment from entering other layers that may be deposited on top of the top surface of the cathode current collector layer 104.

[0026] The template 106 is deposited on the top surface of the cathode current collector layer 104 using a suitable known deposition technique as described above. In one embodiment, the template 106 is deposited on the top surface of the cathode current collector layer 104 and on the sidewalls and bottom of the trenches 108. Once the template 106 is deposited, the template 106 can be patterned using known techniques to remove the template 106 previously deposited in the trenches 108. As a result, the trenches 108 are lined with the cathode current collector layer 104 and are free of any template 106 therein. The template 106 remains only on the top surface of the cathode current collector layer 104, which is located on top of the top surface of the substrate 102.

[0027] The template 106 further defines trenches 108 patterned in the substrate 102. The template 106 causes the sidewalls of the trenches 108 to extend above the cathode current collector layer 104 and the top surface of the substrate 102 because the template 106 remains only on the top surface of the cathode current collector layer 104. As a result, the sidewalls of the template 106 closest to the trenches 108 are substantially aligned with the sidewalls of the trenches 108. The template 106 also protects the cathode current collector layer 104 from deterioration during subsequent processing steps in battery manufacturing.

[0028] Template 106 is also removable and can be made of different polymers. For example, if a low temperature pressing step is subsequently used to form the cathode layer, the template 106 is made of a high temperature compressible polymer. However, if a high temperature pressing step is subsequently used to form the cathode layer, the template is made of a low temperature polymer.

[0029] Reference now Figure 2 , after the template 106 is deposited on the top surface of the cathode current collector layer 104, the cathode layer 110 is deposited into the groove 108. The cathode layer 110 can be made of a lithium-containing material, such as LiCO2, LiMn2O4, LiFePO4 or other suitable cathode materials (such as metal oxides). Once deposited, the cathode layer 110 extends above the top surface of the cathode current collector layer 104, but extends below the top surface of the template 106. In this way, the cathode layer 110 is contained in the groove 108, within the sidewalls created by the template 106, and is in direct contact with portions of the sidewalls of the template 106. In one embodiment, the cathode layer 110 extends above the top surface of the cathode current collector layer 104 so that after further processing, reference is made to Figure 3-4As described, the cathode current collector layer 104 may be substantially flush with the top surface of the cathode current collector layer 104 extending along the top surface of the substrate 102 , which takes into account the initial density of the cathode layer 110 and the final desired density of the cathode layer 110 .

[0030] Reference now Figure 3 , the indenter 112 is located directly above the cathode layer 110. The indenter 112 can be made of the same material as the substrate 102, such as silicon or any other suitable material. The positioning of the indenter 112 is aided by the sidewalls of the template 106 extending above the top surface of the cathode layer 110. As a result, the indenter 112 fits between the areas created by the template 106, directly above the cathode layer 110.

[0031] Once the press head 112 is in place, the press head 112 is used to isostatically press the cathode layer 110 down into the grooves patterned in the substrate 102. When the cathode layer 110 is first deposited into the grooves 108, the cathode layer 110 fills the grooves 108 and extends above the top surface of the cathode current collector layer 104 but below the top surface of the template 106. As a result, more cathode layer 110 is deposited than is needed to just fill the grooves 108. This is done so that the cathode layer 110 can be pressed down into the grooves patterned in the substrate 102, thereby reducing its thickness.

[0032] The isostatic pressing of the cathode layer 110 can be performed at low or high temperatures. In one embodiment, the cathode layer 110 can be isostatically compressed or compacted at a low temperature that is compatible with the template 106. Once the cathode layer 110 is compressed, the template 106 can be removed and the cathode layer 110 can be further compressed and heated. During isostatic pressing, the press head 112 applies equal pressure in all directions and pushes down onto the cathode layer 110, thereby condensing the cathode layer 110.

[0033] Typically, when a cathode is deposited using a deposition process such as sputtering, a mechanical polishing step may be required before depositing additional layers on top of the cathode. The sputtering deposition step may introduce impurities into the cathode. Compressing the cathode layer 110 using the press head 112 produces a dense cathode layer 110 that is free of impurities. After compressing the cathode layer 110 using the press head 112, it has a clean interface that can then be patterned and sealed.

[0034] Additionally, unlike conventional sputtering deposition processes, compressing cathode layer 110 using press head 112 allows for control of the porosity of cathode layer 110. The porosity of cathode layer 110 may be controlled by the properties of the deposited cathode layer 110. For example, the properties of cathode layer 110 may refer to the shape of particles constituting cathode layer 110.

[0035] The porosity of the cathode layer 110 can also be controlled by the amount of pressure applied to the cathode layer 110 by the press head 112. For example, the cathode layer 110 of the same thickness is deposited in two cases. In the first case, if the press head 112 applies more pressure to the cathode layer 110, the cathode layer 110 can be more densely compacted. However, if in the second case, the pressure applied by the press head 112 is less, the cathode layer 110 can be compacted, but its density is less and the porosity is greater.

[0036] The porosity of the cathode layer 110 can be controlled by the duration of compression of the cathode layer 110. For example, the duration of compression of the cathode layer 110 by the press head 112 can produce cathode layers 110 of different densities. For example, the cathode layer 110 of the same thickness is deposited. If the duration of compression is short, the density of the cathode layer 110 can be smaller than the density of the cathode layer 110 when the duration of compression is longer.

[0037] The porosity of the cathode layer 110 can also be controlled by the temperature at which the cathode layer 110 is compressed. During the sintering process, the cathode layer 110 can be compressed. This causes the particles making up the cathode layer 110 to adhere to and bond to each other, thereby forming a cathode layer 110 that is more porous than the cathode layer 110 that was first deposited into the trench (108).

[0038] In addition, the cathode layer 110 can be combined with additives to improve the efficiency of the battery. In one embodiment, the cathode layer 110 can be combined with a low vapor pressure ionic liquid electrolyte to improve the performance of the cathode layer 110. In another embodiment, the cathode layer 110 can be combined with conductive carbon, which can also increase the performance of the cathode layer 110 by increasing its electronic conductivity. In one embodiment, if hot pressing is used to compress the cathode layer 110, the ionic liquid electrolyte can be added to the cathode layer 110 by allowing the ionic liquid electrolyte to flow into the compressed cathode layer 110 via capillary forces. In an alternative embodiment, if cold pressing is used to compress the cathode layer 110, the ionic liquid electrolyte can be incorporated into the cathode layer 110 before compressing the cathode layer with the press head 112.

[0039] Reference now Figure 4, the cathode layer 110 is compressed so that the top surface of the cathode layer 110 is substantially flush with the top surface of the cathode collector layer 104 extending along the top surface of the substrate 102. In order to ensure that sufficient cathode layer 110 is deposited so that when compressed by the press head 112, the cathode layer 110 is substantially flush with the upper surface of the cathode collector layer 104. Typically, when a lithium battery is manufactured, a deposition process, such as sputtering, is used to deposit the cathode layer on top of the cathode collector layer 104. As described above, the thicker the cathode layer 110, the higher the capacity of the battery. Therefore, it is advantageous to manufacture a battery with a thick cathode layer 110. However, conventional deposition processes are time consuming and expensive. The cathode layer 110 is hot-pressed or cold-pressed into the groove 108 ( Figure 1 ), a cathode layer 110 having a desired thickness and density is produced compared to that deposited using conventional techniques, further increasing the capacity of the battery.

[0040] Burying the cathode layer 110 in the substrate 102 also reduces the sealing area of ​​the battery. As described above, when manufacturing conventional batteries, the cathode layer is deposited on top of the cathode collector layer, which is deposited on top of the substrate. As a result, conventional batteries have a stack of layers that need to be sealed. The seal needs to be thicker to accommodate the shape of the cathode. This in turn requires a larger sealing area. In addition, in order to manufacture efficient batteries, the thickness of the cathode layer is increased. This translates into a larger sealing area because the additional layer stack is higher. For a higher layer stack, the sealing area increases to protect these layers from environmental pollution sources.

[0041] In one embodiment, the cathode layer 110 is no longer located on the top surface of the substrate 102. Instead, the cathode layer 110 is buried in the substrate 102, and the top surface of the cathode layer 110 is substantially flush with the top surface of the cathode current collector layer 104. Since the cathode layer 110 is no longer deposited on top of the substrate 102, the additional layer stack is not as high as the layer stack when making a conventional battery in which the cathode layer is deposited on top of the substrate. The shorter layer stack translates into a smaller sealing area. In addition, making a battery with a thicker cathode layer 110 does not increase the height of the stack because the cathode layer 110 can be further buried in the substrate 102 so that the cathode layer 110 does not extend above the top surface of the cathode current collector layer 104.

[0042] In one embodiment, once the cathode layer 110 is uniformly compressed, a surface planarization process may be used to smooth the top surface of the cathode layer 110 and prepare it for further processing.

[0043] Reference now Figure 5Once the cathode layer 110 is compressed, additional layers are deposited onto the top surface of the cathode layer 110 and the cathode current collector layer 104. Standard techniques may be used to achieve the deposition of additional layers. The additional layers may include, but are not limited to, an electrolyte layer 114, an anode layer 116, an anode current collector layer 118, and an insulator layer 120.

[0044] The electrolyte layer 114 may include a solid electrolyte to provide in-situ processing without air interruption. In one embodiment, the electrolyte layer 114 may include a thin solid film, such as LiPON or a spin-on sol, but other materials may also be used. The electrolyte layer may be deposited by evaporation, chemical vapor deposition, sputtering, or other suitable deposition processes. The electrolyte layer 114 may be deposited on the top surface of the cathode layer 110, between the cathode layer 110 and the anode layer 116, separating the layers 110 and 116. The electrolyte layer 114 may provide ionic conduction between the cathode layer 110 and the anode layer 116.

[0045] Anode layer 116 may be deposited on the top surface of electrolyte layer 114. Anode layer 116 may be made of lithium, lithium alloys, or any other suitable material. Anode layer 116 may be deposited by evaporation, chemical vapor deposition, sputtering, or other suitable deposition process.

[0046] Anode collector layer 118 can be deposited on the top surface of anode layer 116. Anode collector layer 118 serves as a current path for anode layer 116. Anode collector layer 118 can be made of non-reactive metal, such as copper, silver, gold, platinum or any other suitable material. Anode collector layer 118 can be deposited by evaporation, chemical vapor deposition, sputtering or other suitable deposition process. In one embodiment, anode collector layer 118 can be in direct contact with substrate 102 to form a seal. In one embodiment, anode collector layer 118 and cathode collector layer 104 are both away from the seal, but not in direct contact with each other.

[0047] An insulator layer 120 may be deposited on the top surface of the anode current collector layer 118. The insulating layer 120 may be made of a conductive material, such as aluminum or any other suitable material. The insulating layer 120 may keep the structure 100 electrically isolated from the external environment.

[0048] Reference now Figure 6, cap layer 122 is deposited onto the top surface of insulating layer 120. Cap layer 122 may be made of the same silicon-based material as the material constituting substrate 102, such as silicon, silicon germanium carbon, silicon carbon, and multilayers thereof. Cover layer 122 may also be made of any combination of materials that exhibit low permeability to oxygen, water, and other substances that damage the battery. Illustrative examples of such materials may include, but are not limited to, metal films, multilayer metal films, insulating films, multilayer insulating films, or multilayer metal and insulating films. Cap layer 122 may be formed by chemical vapor deposition, sputtering, evaporation, or any other suitable deposition process.

[0049] Capping layer 122 covers cathode current collector layer 104, cathode layer 110, electrolyte layer 114, anode layer 116, anode current collector layer 118, and insulator layer 120. Capping layer 122 protects these layers from exposure to environmental elements, corrosion, or other damage. In one embodiment, capping layer 122 is deposited on top of insulator layer 120. In an alternative embodiment, capping layer 122 is not deposited on insulator layer 120. Instead, insulator layer 120 is the topmost layer in structure 100. However, it is more beneficial to have capping layer 122 cover other layers including insulator layer 120 because capping layer 122 protects structure 100 from environmental elements better than insulator layer 120, thereby increasing the shelf life of structure 100.

[0050] In conventional batteries, in order to access the cathode or anode, isolated through holes are usually patterned through any insulator or isolation layer. In addition, contacts are usually formed on the anode side of the battery. In an embodiment, for example, an anode contact can be made by patterning an isolated through hole through the insulator layer 120. However, the cathode contact can be made using a conductive cathode substrate, such as degenerate doped silicon. When a conductive cathode substrate is used, the cathode collector layer 104 can form an ohmic contact with the substrate 102, allowing the back ohmic metal contact to be patterned. When compared with the conventional anode side (or front side) contact scheme, the back side contact occupies less area, thereby allowing more area to be used for electrochemical materials.

[0051] Reference now Figure 7 , a structure 200 is shown. The structure 200 represents multiple structures 100 or cells fabricated side by side on a single wafer. Although only two structures 100 are shown, embodiments of the present invention contemplate multiple structures 100 fabricated on a single substrate 102, as referred to herein. Figure 1-6 described.

[0052] Reference now Fig. 8A and 8B , which all show a structure 200 having more than two cells (100). Figure A shows a structure 200 manufactured using a conventional sputtering process, Figure 8B1 represents a structure 200 made according to the present invention. The structure 200 may include a plurality of cells, each cell including a cathode layer 110. It should be noted that for the sake of clarity and understanding, Fig. 8A and 8B Other components of the battery (100) are omitted. After forming the battery (100), the structure 200 can be cut or sliced ​​along line 124 to produce a plurality of individual batteries. As described above, the manufacture of the battery using a conventional sputtering process produces a battery having a larger sealing area relative to the area of ​​its cathode layer 110 due to the stacking of layers that need to be sealed and protected from environmental contaminants. In addition, when separating into individual batteries, a large sealing area is also required to protect the integrity of the layers during cutting of the structure 200. Therefore, compared to batteries manufactured according to the present invention, conventional methods produce batteries having a relatively small cathode layer 110 and a relatively large sealing area.

[0053] As mentioned above Figure 1-6 As stated, and as Figure 8B As shown, by burying the cathode layer 110 in the substrate 102, the size of the cathode 110 can be increased and the sealing area can be reduced / reduced while maintaining the same cutting footprint. Since the cathode layer 110 no longer extends above the substrate 102, there are fewer layers stacked, thereby reducing the sealing width while maintaining the functional and physical integrity of the individual battery structure (100). Due to the reduced size of the sealing area / width, the cathode layer 110 can be increased (width / length), thereby increasing the capacity of the battery.

[0054] Furthermore, during the etching of the trenches in the substrate 102 ( Figure 1 ), the cutting channel 126 can also be etched into the substrate 102 at the same time. The cutting channel 126 can be located between each structure 100 ( Figure 7 ) and define the edges of each structure 100. The dicing channels 126 are small channels in the substrate 102 that facilitate dicing the substrate to form individual structures 100.

[0055] Embodiments of the present invention incorporate cutting channels 126 to reduce the stress applied when structure 200 is cut into individual cells (structure 100). Cutting channels 126 allow each cell to maintain its sealing integrity. In addition, since a large sealing area is no longer required, each cathode layer 110 can be made larger. Therefore, in the case of including cutting channels 126 and burying cathode layer 110 in substrate 102, embodiments of the present invention provide a battery having a reduced ratio between the seal and cathode layer 110 of the battery compared to the ratio between the seal and cathode layer of a conventional battery. Therefore, the total surface area of ​​the battery is also reduced compared to the total surface area of ​​a conventional battery.

[0056] The description of various embodiments of the present invention has been given for the purpose of illustration, but it is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or technical improvements existing in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for forming a thin film battery, the method comprising: forming a trench in a substrate; depositing a cathode current collector layer along the sidewalls and bottom of the trench, wherein the substrate is degenerately doped silicon in ohmic contact with the cathode current collector layer and is configured to allow a backside ohmic metal contact to be patterned; depositing a template on a top surface of the substrate, wherein the template is aligned with the trench; depositing a cathode layer in the trench, wherein the cathode layer is in direct contact with the template; and The cathode layer is isostatically pressed into the groove to reduce the thickness of the cathode layer, the cathode layer is combined with a liquid electrolyte additive and is positioned in the groove along the cathode current collector layer, wherein the top surface of the cathode layer is substantially flush with the top surface of the cathode current collector layer, and wherein the cathode layer has a given density and porosity based on the pressure and duration associated with the isostatic pressing.

2. The method of claim 1 , wherein depositing the cathode layer in the trench further comprises: The cathode layer is deposited along a portion of a sidewall of the template.

3. The method of claim 1 , wherein compressing the cathode layer into the groove further comprises: An isostatic pressure is applied to the cathode layer using an indenter.

4. The method according to claim 1, further comprising: depositing an electrolyte layer on top of the cathode layer; depositing an anode layer on top of the electrolyte layer; as well as On top of the anode layer an anode current collector layer is deposited. The method of claim 1 , wherein the template is made of a high temperature polymer or a low temperature polymer.

6. The method according to claim 1, further comprising: An ionic liquid electrolyte is added to the cathode layer.

7. A method of forming a plurality of thin film batteries, the method comprising: forming a plurality of trenches in a substrate, each trench corresponding to a different one of the cells; forming a plurality of cutting channels in the substrate, wherein each of the plurality of cutting channels is located between each of the plurality of trenches; as well as, Each of the cells is formed according to the method of any one of the preceding claims.

8. The method according to claim 7, wherein: The plurality of dicing channels are formed in the substrate using reactive ion etching.

9. A structure comprising: a cathode current collector layer positioned along a substrate and along the bottom and sidewalls of a trench in the substrate, wherein the substrate is degenerate doped silicon in ohmic contact with the cathode current collector layer and is configured to allow a backside ohmic metal contact to be patterned; one or more scribe lanes etched into the substrate, wherein the one or more scribe lanes are configured to define edges of the structure and reduce stress associated with scribe of the structure; and A cathode layer is isostatically pressed and buried in the grooves in the substrate, combined with a liquid electrolyte additive and positioned in the grooves along the cathode current collector layer, wherein the top surface of the cathode layer is substantially flush with the top surface of the cathode current collector layer, and wherein the cathode layer has a given density and porosity based on the pressure and duration associated with the isostatic pressing.

10. The structure according to claim 9, further comprising: an anode layer located on top of an electrolyte layer, wherein the electrolyte layer separates the cathode layer from the anode layer; an anode current collector layer located on top of the anode layer; as well as An insulator layer is located on top of the anode current collector layer.

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