JPH05293965A - Three-dimensional silicon structure - Google Patents

Abstract

PURPOSE: To provide a three-dimensional structure which can be used as a silicon nozzle with a feed channel. CONSTITUTION: A three-dimensional silicon structure comprises a first silicon part 1 having an opening 6 and a second silicon part 2 having a channel 14. Both silicon parts are joined by a bonding process so that the channel 14 is located on the opening 6.

Description

Detailed Description of the Invention

[0001]

The invention starts from a three-dimensional silicon structure according to the category of claim 1.

[0002]

2. Description of the Related Art Three-dimensional silicon structures produced by bonding stacked silicon wafers using a bonding technique are already known (Csepregi).
L. in Heuberger A. , "Mikrom
echanik ", Springer-Verlag,
1989, pp. 230-234). However, these structures are largely limited to planar structural components.

[0003]

On the other hand, the three-dimensional silicon structure according to the present invention having the features described in the characterizing part of claim 1 has the third dimension well clarified, and therefore other than planar structural parts. Has the advantage that it can also be applied. The resulting degree of freedom in structuring silicon can also be used in modern silicon structural parts.

The features described in the dependent claims enable advantageous constructions and improvements of the three-dimensional silicon structure described in claim 1. The structuring possibilities are once again expanded by the use of silicon components produced by the bonding of two silicon wafers themselves. Such structural components are particularly suitable for producing high-precision passages. These passages are provided particularly simply for each application case by splitting the wafer parts and then grinding the cut surfaces. A nozzle having a feed channel is manufactured by joining the passage with a silicon component having holes. Therefore, the silicon structure according to the invention makes it possible to manufacture fluidic elements, channels and nozzles in a particularly advantageous and highly structured manner.

One embodiment of the present invention is shown in the drawings and detailed below.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a first silicon part is designated by 1 and a second silicon part is designated by 2. The first silicon part has holes 6. The second silicon part consists of two pieces 11, 12
And has a passage 14. The passage 14 extends through the entire second silicon component. Silicon part 1 and silicon part 2 are connected to each other, as indicated by the arrow. This bonding is carried out by bonding the surface 4 of the first silicon structural component 1 and the end surface 5 of the second silicon structural component 2 which covers the surface. Both surfaces 4, 5 are
Properly prepared for bonding. Both surfaces 4, 5 must be sufficiently flat. The surface 4 representing the surface of the silicon wafer is manufactured by the wafer manufacturer.
It has a sufficiently good surface quality by polishing or etching. Producing a sufficiently flat surface 5 is done by machining. Surfaces for bonding 4, 5
Another method of preparation of the above involves thin layer sputtering of sodium-containing glass, thermal oxidation of a silicon dioxide layer or hydrophilization of the silicon surface. The actual bonding consists of applying a voltage and / or heat treatment to both structural parts. Corresponding bonding is described in the first cited document. The geometry of the holes 6 is not compulsorily defined. Anisotropic wet chemical etching is 11
It is possible to make parallel elongated slits with walls oriented in 0-silicon perpendicular to the surface,
In 100-silicon, the sidewalls have an angle to the surface of about 55 °. The bidirectional anisotropic etching of the silicon part can also create holes whose minimum cross section is within the silicon part 1 for 100-silicon. However, in wet chemical etching, the geometry of the holes 6 is constrained by the crystal structure of silicon. The use of anisotropic plasma etching, such as reactive ion etching,
It is possible to make holes 6 of any shape in plan view, with almost vertical walls. By using anisotropic etching,
It is likewise possible to make the holes 6 of any shape, but in this case the angle of the side wall with respect to the surface 4 depends on the shape of the holes 6.

Similarly, a hole 6 or a passage 1 having a hole 6
A multiple arrangement of 4 is also conceivable. In this case, several holes 6 may belong to one passage 14 or several passages 14 may be arranged in parallel with one or several holes 6, respectively. In the latter case, by dividing this structure, a large number of individual channels 14 with holes 6 can be created simultaneously.

The three-dimensional silicon structure shown here can be used as a silicon nozzle having a supply passage. By using anisotropic etching, these nozzles can be manufactured with great precision. Due to the chemical passivation and high heat resistance of silicon, these nozzles can also be used in corrosive environments, for example as benzine injection nozzles.

In FIG. 2, two overlapping wafers 2 are shown.
The production of a second silicon part 2 consisting of 1, 22 is shown. The groove provided in the wafers 21, 22 is indicated by 13. A passage 14 is formed during bonding by closing the groove 13 with the other wafer or by overlapping the two grooves. By dividing the wafer along the line 15, a second silicon part 2 is produced, the cuts 16 defining the number of passages 14 in the second silicon part 2. The wafer 21 produced by the cutting 15,
At least one surface perpendicular to the surface of 22 is post-processed into a surface 5 suitable for bonding by a suitable method.

The cross section of the passage 14 results from the geometry of the groove 13. By anisotropic etching, a V-shaped groove having an opening angle of about 70 ° in 100-silicon was formed into 110.
It is possible to create grooves with vertical walls in silicon. The groove depth in 110-silicon is formed with great precision by the buried etch stop layer. The anisotropic etching technique results in an approximately semi-circular cross section of the groove 13. Dividing the passageway 14 along the cutting line 15 is done by using a diamond saw or a laser beam. The quality of the surface obtained in this case is usually unsuitable for the bonding method. A sufficiently good surface quality is achieved by mechanical post-processing, such as lapping or polishing. The wafer 21 along the cutting line 16,
22 is divided into a certain number of passages 1 in the silicon structural component
There is a problem that 4 is provided. The cutting 16 is performed by sawing, but can be performed by anisotropic wet chemical etching. For example, in the case of a silicon structural component having two passages 14, only a second cut 16 is made in each case.

[Brief description of drawings]

FIG. 1 is a perspective view of a silicon structure according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a second silicon part during manufacturing.

[Explanation of symbols]

 1 1st silicon part 2 2nd silicon part 4,5 Surface 6 Hole 11,12 Divided piece 13 Groove 14 Passage 15 Cutting line 16 Cutting 21,22 Wafer

Claims (7)

[Claims] 1. A three-dimensional silicon structure in which at least two silicon parts are bonded to each other by bonding, the silicon parts (1, 2) being manufactured from a silicon wafer, the first silicon part (1). ) Has a high quality surface (4) formed from the surface of a silicon wafer, and the second silicon part (2) has a high surface quality which is perpendicular to the wafer surface of this silicon part (2). A three-dimensional silicon structure, characterized in that it has a surface (5) having both parts (1, 2) bonded by bonding on the surface (4,5). 2. The three-dimensional silicon structure according to claim 1, wherein the second silicon part (2) is manufactured by bonding two silicon wafers (21, 22). 3. A silicon wafer (22), characterized in that one of the silicon wafers (22) has a groove which is closed during bonding so that the other silicon wafer (21) produces a passage (14). The three-dimensional silicon structure according to item 2. 4. Two silicon wafers (21, 22)
3. The three-dimensional silicon structure according to claim 2, characterized in that each has one groove (13), said grooves overlapping in mirror image during bonding to give at least one passage (14). 5. At least one passage (14) has a cutting line
A three-dimensional silicon structure according to claim 3 or 4, characterized in that it is divided perpendicularly to the surfaces of the two bonded wafers (21, 22) by (15). 6. The three-dimensional silicon structure according to claim 5, wherein the cross section produced by the cutting is post-processed to a surface having high surface quality by polishing and / or lapping. 7. The first silicon part (1) has at least one hole (6), at least one hole being at least one.
Three-dimensional silicon structure according to any one of the preceding claims, characterized in that it is smaller than one passage (14) and the holes (6) and passages (14) overlap during bonding. ..