Method for producing semiconductor component and micromirror assembly

Abstract

The invention relates to a method for producing a semiconductor component, in particular having a microstructure. In this case, a semiconductor chip (156) is produced, which has an outer frame structure (150) of the semiconductor chip (156) that is connected to the semiconductor chip (156) by means of a circumferential trench (155). The semiconductor chip (156) is also moved to the next process step by means of a tool, in particular a vacuum gripper, acting on the outer frame structure (150) of the semiconductor chip (156). In addition, the resulting outer frame structure (150) of the semiconductor chip (156) is removed.

Description

Technical Field

[0001] The invention relates to a method for producing a semiconductor component and a micromirror assembly produced by means of the method. Background Art

[0002] US 2018 / 0022603 A1 discloses a method for manufacturing a MEMS device in which individual MEMS chips are separated from the rest of the MEMS wafer by forming a partially continuous trench structure, with individual tabs remaining as connecting structures. Thus, the individual chips can be separated into individual components after manufacturing by being removed from the MEMS wafer. Summary of the Invention

[0003] Starting from this, the object of the present invention is to develop a method for producing a semiconductor component in which already separated chips can be moved by means of a tool without losing valuable chip surface and without contacting sensitive chip surfaces.

[0004] To achieve this object, a method for producing a semiconductor component, in particular one having a microstructure, is proposed according to claim 1. A micromirror assembly produced by means of this method is also proposed according to claim 14.

[0005] In a method for manufacturing a semiconductor component, particularly one having a microstructure, a semiconductor chip is first produced that includes an outer frame structure of the semiconductor chip that is connected to the semiconductor chip via a circumferential groove. In this case, the frame structure, in a top view, particularly surrounds or encloses the semiconductor chip frame. In another method step, the semiconductor chip is moved to the next process step using a tool that acts on the outer frame structure of the semiconductor chip. This tool is particularly a vacuum gripper, also known as a vacuum pick-up tool (PUT) in English. In the final method step, the outer frame structure of the semiconductor chip is removed again. In order to move the semiconductor chip, which is preferably constructed of silicon, a frame structure is used that is located outside the active chip area so that the active chip area can be fully utilized in further processing steps. The outer frame structure also prevents the chip area, particularly the active chip area, from being damaged by the tool that acts during movement.

[0006] Preferably, the circumferential trench of the semiconductor chip is produced by means of a semiconductor chip etching process. In this context, the circumferential trench of the semiconductor chip is produced in particular by means of a semiconductor wafer etching process, in particular a trench process, for producing the semiconductor chip from a semiconductor wafer. The trench is produced in particular at the wafer level, and therefore already before the semiconductor chips are separated.

[0007] Preferably, the circumferential trench section is continuously produced, in particular through the semiconductor substrate, so that the outer frame structure is connected to the semiconductor chip by means of at least one connecting web. The connection of the semiconductor chip to the outer frame structure allows the outer frame structure to be removed as simply as possible later, in particular by removing the semiconductor chip from the frame structure.

[0008] Preferably, a plurality of semiconductor chips are produced from a semiconductor substrate. In this context, in particular, a plurality of circumferential trenches are produced around a plurality of corresponding regions of the semiconductor wafer. Subsequently, these regions, each having a circumferential trench and each having an additional edge region surrounding the circumferential trench, are separated from the semiconductor substrate. This edge region then forms the outer frame structure of the semiconductor chip.

[0009] Preferably, the outer side of the semiconductor chip and the outer frame structure lie planarly in one plane. Alternatively, the outer frame can also be partially thinned or protrude outward from the main extension plane of the semiconductor chip.

[0010] Preferably, the semiconductor chip is moved onto at least one other component of the semiconductor component by means of a tool acting on the outer frame structure of the semiconductor chip and connected thereto. The other component may be, for example, a carrier substrate for the semiconductor component.

[0011] Preferably, in a further method step, the outer side of the semiconductor chip is treated in such a way that, after treatment, it is mechanically sensitive. The outer frame structure enables such a semiconductor to be moved, in particular to further process steps, without tools acting on the sensitive outer side of the semiconductor chip. Preferably, in conjunction with this treatment, a coating, in particular a reflective coating, is applied to the mechanically sensitive outer side of the semiconductor chip. Such coatings, which are often used in optical applications, are highly sensitive to mechanical loads.

[0012] Preferably, the semiconductor chip, in particular the mechanically sensitive outer side of the semiconductor, and the outer frame structure are additionally covered by a protective cover. In this case, the protective cover is connected only to the outer frame structure. In a further method step, the protective cover is removed together with the resulting outer frame of the semiconductor chip. The protective cover serves, in particular, to protect the semiconductor chip from external environmental influences. In particular, the protective cover being connected only to the outer frame structure and not to the semiconductor chip has the advantage that the protective cover is also removed from the semiconductor chip when the frame structure is removed. Consequently, no additional fastening means for the protective cover to the semiconductor chip are required.

[0013] Preferably, the semiconductor chip is moved during a pick-and-place process by means of a tool acting on the outer frame structure of the semiconductor chip. In this context, the semiconductor chip is preferably positioned in a carrier, in particular a carrier, during the pick-and-place process, with at least one mechanically load-sensitive outer side of the semiconductor chip facing the carrier. In this context, the outer frame structure preferably protrudes outward from the plane of the mechanically load-sensitive outer side of the semiconductor chip, so that the sensitive outer side does not come into contact with the carrier. Alternatively, the aforementioned protective cover can also be used to protect the mechanically load-sensitive outer side of the semiconductor chip from contact with the carrier.

[0014] When removing the resulting outer frame structure of the semiconductor chip, the outer side of the semiconductor chip, which is sensitive to mechanical loads, is preferably oriented in the direction of the Earth's surface. The weight of the outer frame structure then causes it to fall downward, for example after it has been cut off or dismantled. This simplifies the removal process of the outer frame structure.

[0015] Preferably, a micromirror assembly is also produced from a semiconductor chip. The micromirror assembly is, in particular, a micromirror array. The EPyC process is particularly used in the manufacture of such micromirror arrays. An EPyC cycle consists of depositing a polysilicon layer, structuring trenches in the silicon layer, oxide filling by thermal oxidation and TEOS deposition, and finally, oxide opening. This cycle is repeated multiple times until the entire 3D-MEMS structure is constructed. Finally, a sacrificial layer of silicon and oxide is etched to release the movable microstructures.

[0016] Another subject matter of this application is a micromirror assembly manufactured using the method described above. The micromirror assembly comprises a plurality of independently operable individual mirror elements arranged in a field, particularly an array. The individual mirror elements can be moved via an actuator, particularly actuator electrodes. Each individual mirror element has a reflective surface and is separated from one another by gaps. The micromirror assembly also comprises a carrier substrate for the micromirror assembly. The individual mirror elements, together with the gaps between them, have a total area, particularly in the main extension plane of the micromirror assembly. This total area of ​​the field of individual mirror elements corresponds to at least one total area of ​​the carrier substrate, particularly oriented in the main extension plane of the carrier substrate. This frameless embodiment of the micromirror assembly enables the largest possible fill factor for the field of individual mirror elements. Preferably, in this context, the individual mirror elements are arranged in a rectangular field and the carrier substrate is square in shape. The micromirror assembly is also preferably square in shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A method for producing a semiconductor component is shown.

[0018] Figure 2 A micromirror assembly with an external frame structure is shown.

[0019] Figure 3 A micromirror assembly manufactured according to the present method is shown.

[0020] Figure 4 The fabricated micromirror assembly is shown with a protective cover attached.

[0021] Figure 5 Shown is a cross section of a single mirror element of a micromirror assembly. DETAILED DESCRIPTION

[0022] Figure 1 A method for producing a semiconductor component, in particular one having a microstructure, is schematically illustrated using a flow chart. In this case, a semiconductor chip, in particular made of silicon, is first produced in method step 30 , which includes an outer frame structure of the semiconductor chip connected to the semiconductor chip via a circumferential trench. Following method step 30 , in method step 80 , the semiconductor chip is further moved to the next process step using a tool, in particular a vacuum gripper, acting on the outer frame structure of the semiconductor chip. In a subsequent method step 100 , the produced outer frame structure of the semiconductor chip is removed. The method then ends.

[0023] In an optional method step 40 following method step 30, a trench surrounding the semiconductor chip is produced by an etching process, in particular of a semiconductor wafer containing the semiconductor chip. Furthermore, the trench surrounding the semiconductor chip is produced partially continuously, in particular through the semiconductor substrate, so that the outer frame structure is connected to the semiconductor chip by means of at least one connecting web.

[0024] In another optional method step 50, a plurality of semiconductor chips are produced from a semiconductor substrate. In this context, a plurality of surrounding trenches, in particular, are produced around a plurality of corresponding regions of a semiconductor wafer. Subsequently, these regions, each having a surrounding trench and each having an additional edge region surrounding the surrounding trench, are separated from the semiconductor substrate. The edge region then forms the outer frame structure of the semiconductor chip.

[0025] In a further optional method step 90, the semiconductor chip is moved onto at least one other component of the semiconductor assembly by means of a tool acting on the outer frame structure of the semiconductor chip and subsequently connected to the other component. In this case, this is particularly a pick-and-place process. In this context, it occurs in particular that the semiconductor chip is positioned in a carrier, in particular a carrier, by the pick-and-place process, with at least one outer side of the semiconductor chip, which is sensitive to mechanical loads, facing in the direction of the carrier.

[0026] In another optional method step 60 , the outer side of the semiconductor chip is treated so that it is then sensitive to mechanical loads. Optionally, in this context, a coating, in particular a reflective coating, is applied to the mechanically sensitive outer side of the semiconductor chip.

[0027] Optionally, the semiconductor chip, in particular the mechanically sensitive outer side of the semiconductor chip and the outer frame structure, can also be covered with a protective cap in method step 70. In this case, the protective cap is only connected to the outer frame structure and is removed together with the resulting outer frame structure of the semiconductor chip in method step 100.

[0028] In a further, optional method step 110 following method step 100 , the outer side of the semiconductor chip, which is sensitive with respect to mechanical loads, is oriented in the direction of the Earth's surface when the resulting outer frame structure of the semiconductor chip is removed.

[0029] Alternatively, the micromirror assembly, in particular the micromirror array, is produced from a semiconductor chip.

[0030] Figure 2 A micromirror assembly 151 is shown in a top view as a semiconductor component with an outer frame structure 150. The outer frame structure 150 is connected to a semiconductor chip 156 of the micromirror assembly 151 via connecting tabs 180. A partially continuous, circumferential groove 155 is arranged between the outer frame structure 150 and the semiconductor chip 156. The micromirror assembly 151 is designed as a micromirror array in this case. The micromirror assembly 151 has a plurality of individual mirror elements 160 that can be controlled independently of one another and are arranged in a field, in particular an array. The outer side 158 of the semiconductor chip shown is the outer side 158 that is sensitive to mechanical loads due to the reflective coating 157 of the individual mirror elements 160. Each individual mirror element 160 has a reflective surface and the individual mirror elements 160 are separated from one another by gaps 165. The individual mirror elements 160 together with the gaps 165 between the individual mirror elements 160 have a total area 170, for example Figure 3 As can be seen from the figure, this total area corresponds to at least one total area of ​​the carrier substrate 310 for the micromirror assembly 151. The micromirror assembly 151 without the external frame structure 150 is Figure 3 The above corresponds to the Figure 1 The micromirror assembly 151 is manufactured by the method described above.

[0031] Figure 4 Show the basis Figure 2 The present invention relates to a micromirror assembly having an outer frame structure 150, with the difference that in this case the outer frame structure 150 is additionally covered by a protective cover 200. The protective cover 200 is connected only to the outer frame structure 150 in this case.

[0032] Figure 5 A schematic diagram of a single mirror element 290 of a micromirror assembly 205 is schematically shown. The single mirror element 290 has a mirror surface or reflective surface 255 that forms a mirror plate 260. Below the mirror surface or reflective surface is a carrier plate 250. The carrier plate 250 is provided with a plurality of movable passive electrodes 295. The movable passive electrodes 295 each include, on the one hand, sensor electrodes / detector electrodes arranged in an annular arrangement 270 and constructed along an inner ring, and, on the other hand, actuator electrodes arranged in an annular arrangement 265, 270. The sensor electrodes or actuator electrodes arranged in the annular arrangement 265, 270 form the movable passive electrode 295. On the base plate 240, which can be surrounded by a frame structure 245 to avoid crosstalk effects, there is a fixed active electrode 300, which can also be arranged in an annular arrangement 265, 270. The listed movable passive electrodes 295 and the fixed active electrodes 300 , which are arranged in annular arrangements 265 , 270 on the carrier plate 250 or on the base plate 240 , respectively, mesh with one another in a comb-like manner.

Claims

1. A method for producing a semiconductor component, in particular one having a microstructure, wherein: The method comprises the following method steps: - producing (30) a semiconductor chip (156) having an outer frame structure (150) of the semiconductor chip (156) connected to the semiconductor chip (156) via a surrounding trench (155), - moving (80) the semiconductor chip (156) to the next process step by means of a tool, in particular a vacuum gripper, acting on the outer frame structure (150) of the semiconductor chip (156), and - Removing (100) the resulting outer frame structure (150) of the semiconductor chip (156).

2. The method according to claim 1, characterized in that The semiconductor chip (156) is made of silicon.

3. The method according to claim 1 or 2, characterized in that The circumferential trench (155) of the semiconductor chip (156) is produced (40) by means of an etching process, in particular of a semiconductor wafer of the semiconductor chip (156).

4. The method according to any one of claims 1 to 3, characterized in that The circumferential trench (156) is produced partially continuously, in particular through the semiconductor substrate, so that the outer frame structure (150) is connected to the semiconductor chip (156) by means of at least one connecting web (180).

5. The method according to any one of claims 1 to 4, characterized in that A plurality of semiconductor chips (156) are produced (50) from a semiconductor substrate.

6. The method according to any one of claims 1 to 5, characterized in that The semiconductor chip (156) is moved (90) onto at least one other component of the semiconductor assembly by means of the tool acting on the outer frame structure (150) of the semiconductor chip (156) and subsequently connected to the other component.

7. The method according to any one of claims 1 to 6, characterized in that The method has the following additional method steps: - treating (60) the outer side (158) of the semiconductor chip (156) in such a way that the outer side (158) is sensitive to mechanical loads.

8. The method according to claim 7, characterized in that A coating, in particular a reflective coating (157), is applied to the outer side (158) of the semiconductor chip (156) which is sensitive with respect to mechanical loads.

9. The method according to any one of claims 1 to 8, characterized in that The semiconductor chip (156), in particular the outer side (158) of the semiconductor chip (156) which is sensitive to mechanical loads, and the outer frame structure (150) are additionally covered (70) with a protective cover (200), wherein the protective cover (200) is connected only to the outer frame structure (150) and is removed (100) together with the resulting outer frame structure (150) of the semiconductor chip (156) in a further method step.

10. The method according to any one of claims 1 to 9, characterized in that The semiconductor chip (156) can be moved by a pick-and-place process by means of a tool acting on the outer frame structure (150) of the semiconductor chip (156).

11. The method according to claim 10, characterized in that The semiconductor chip (156) is positioned in the carrier, in particular a holder, as a result of the pick-and-place process, with at least one outer side (158) of the semiconductor chip (156) being sensitive to mechanical loads facing in the carrier.

12. The method according to any one of claims 1 to 11, characterized in that When the resulting outer frame structure (150) of the semiconductor chip (156) is removed, the outer side (158) of the semiconductor chip (156) that is sensitive to mechanical loads is oriented (110) in the direction of the Earth's surface.

13. The method according to any one of claims 1 to 12, characterized in that A micromirror assembly (151, 205), in particular a micromirror array, is also produced from the semiconductor chip (156).

14. A micromirror assembly (151, 205) produced by means of a method according to any one of claims 1 to 13, comprising a plurality of individual mirror elements (160) which can be actuated independently of one another, the individual mirror elements being arranged in a field, in particular an array, and each being movable via an actuator mechanism, in particular an actuator electrode, and the individual mirror elements (160) each having a reflective surface, and the individual mirror elements (160) each being separated from one another by gaps (165), and comprising a carrier substrate (310) for the micromirror assembly (151, 205), characterized in that: The individual mirror elements (160) together with the gaps (165) between the individual mirror elements (160) have a total area, in particular in a main extension plane of the micromirror assembly (151, 205), which corresponds to the total area of ​​at least one of the carrier substrates (310), in particular in a main extension plane of the carrier substrate (310).

15. The micromirror assembly (151, 205) according to claim 14, characterized in that The individual mirror elements (160) are arranged in a rectangular field and the carrier substrate (310) is of square design.

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