CN203100675U

CN203100675U - MEMS optical interference platform

Info

Publication number: CN203100675U
Application number: CN 201220568198
Authority: CN
Inventors: 陈巧; 谢会开; 周亮
Original assignee: WUXI WIO TECHNOLOGY Co Ltd
Current assignee: WUXI WIO TECHNOLOGY Co Ltd
Priority date: 2012-10-31
Filing date: 2012-10-31
Publication date: 2013-07-31
Anticipated expiration: 2022-10-31

Abstract

The utility model discloses an MEMS optical interference platform. The MEMS optical interference platform comprises a silicon wafer pedestal, a second lens body, a first lens body, actuating arms and a blocking member, wherein the silicon wafer pedestal is provided with an alignment groove, the blocking member is placed in the alignment groove, one side of the silicon wafer pedestal is connected with the second lens body through a first set of actuating arms, and an adjacent side is connected with the first lens through a second set of actuating arms. The first lens body, the second lens body and the blocking member are placed on the same silicon wafer pedestal, forming an optical interference platform module, and reducing assembling difficulty of an interferometer; both the first lens body and the second lens body adopt MEMS micromirrors of a relatively small size, the interference platform that is formed is also relatively small in size, and the cost is low; semiconductor processing technology is used, and alignment is relatively accurate, decreasing assembling errors; the movement range and speed of the MEMS movable lens can be controlled by controlling technological parameters of the actuating arms; and the miniature interference module can be widely applied to various optical systems.

Description

A kind of MEMS optical interference platform

Technical field

The utility model belongs to the MEMS (micro electro mechanical system) field, relates to a kind of MEMS optical interference platform.

Background technology

The principle of work of interferometer is: the light beam that sends from laser instrument, behind beam-expanding collimation, be divided into two-way by spectroscope, and reflect from stationary mirror and moving reflector respectively, merge in afterwards and produce interference fringe on the spectroscope, and observe change of interference fringes by mobile moving reflector.Laser interferometer cooperates various refracting telescopes and catoptron can be used for measure linear position, speed, angle, true Pingdu, straigheness, the depth of parallelism and verticality etc., and can be used as the aligning tool of precision instrument machine or surveying instrument.And interfere platform is the core component of laser interferometer, the conventional interference platform is made up of stationary mirror, moving reflector and spectroscope, said fixing catoptron, moving reflector and spectroscope space are built to form and are interfered platform, because its size is bigger, assembling and debug process complexity, it is lower to adjust precision, the cost height, and then influenced the cost performance of laser interferometer.

The utility model content

The utility model is big for the volume that solves traditional interference platform and exist, assembling and adjustment process complexity, and problems such as the low and cost height of precision propose a kind of MEMS optical interference platform.

For reaching this purpose, the utility model by the following technical solutions:

A kind of MEMS optical interference platform, described MEMS interfere platform to comprise silicon chip pedestal, the second mirror body, the first mirror body, at least two group actuating arm and block pieces, wherein, offer alignment slot on the described silicon chip pedestal, and described block piece is arranged in the described alignment slot; One side of described silicon chip pedestal connects the second mirror body by first group of actuating arm, and an adjacent side connects the first mirror body by second group of actuating arm.

Further, described silicon chip pedestal has upper strata and bottom, described alignment slot is the rectangular recess that is arranged on the upper strata of described silicon chip pedestal, two adjacent edges of this alignment slot are arranged in the upper strata of described silicon chip pedestal and become 90 ° of right angles, and two adjacent edges then are set to be in the same level respectively with two adjacent side of the bottom of described silicon chip pedestal in addition; The bottom of the upper strata of described silicon chip pedestal, described alignment slot and described silicon chip pedestal forms step structure.

Further, the described first mirror body is index glass or fixed mirror, and the described second mirror body is an index glass.

Further, described alignment slot processes by the mode of semiconductor etching.

Further, the described second mirror body is connected on the bottom of silicon chip pedestal by first group of actuating arm, and the described first mirror body is connected on the bottom of silicon chip pedestal by second group of actuating arm; And the described second mirror body is vertical mutually with the plane at the described first mirror body place.

Further, the described first mirror body and the second mirror body are the MEMS micro mirror of electrothermal drive.

Further, the described actuating arm double-layer films material of serving as reasons is at least formed, and every layer film material coefficient of thermal expansion coefficient difference.

Further, described actuating arm is a double-decker up and down, and one deck is a metal level, and another layer is an oxide skin(coating).

Further, the deflection angle of described actuating arm is by its thickness, length and width and temperature control, and its maximum deflection angle is greater than 90 °.

Further, described block piece is spectroscope or block and spectroscopical assembly.

Further, described MEMS micro mirror comprises mirror body, frame and is connected mirror body actuating arm between mirror body and the frame, and described mirror body actuating arm is the actuating arm that electrothermal method drives, and described mirror body actuating arm has the material layer structures same with described actuating arm.

The beneficial effects of the utility model are:

(1) the utility model is placed on the first mirror body, the second mirror body and block piece on the same silicon chip pedestal, forms one and interferes console module, reduces the assembling difficulty of interferometer;

(2) the first mirror bodies and the second mirror body all adopt the less MEMS micro mirror of volume, and the interference platform by volume of formation also can be smaller, and cost is low;

(3) utilize semiconducter process, can more accurately align, reduce assembly error;

(4) control moving of MEMS index glass by the technological parameter of controlling and driving arm, can more accurately observe the interference situation.

Description of drawings

Fig. 1 is that a kind of MEMS of the utility model interferes platform and integrally structural representation one;

Fig. 2 is that a kind of MEMS of the utility model interferes platform and integrally structural representation two;

Fig. 3 is the MEMS of the inclination certainly micro mirror synoptic diagram among Fig. 1 and Fig. 2;

Fig. 4 is the MEMS of the inclination certainly micro-mirror structure sectional view among Fig. 1 and Fig. 2;

Fig. 5 is the MEMS of the inclination certainly micro-mirror structure synoptic diagram among Fig. 1 and Fig. 2;

Fig. 6 is the MEMS of the inclination certainly micro mirror height control synoptic diagram among Fig. 1 and Fig. 2;

Fig. 7 is the MEMS of the inclination certainly micro mirror deflection front and back synoptic diagram among Fig. 1 and Fig. 2;

Fig. 8 is the MEMS micro-mirror structure synoptic diagram among Fig. 1 and Fig. 2;

Fig. 9 is the A-A cut-open view of the MEMS micro-mirror structure among Fig. 8;

Figure 10 is the MEMS micro mirror process synoptic diagram among Fig. 1 and Fig. 2.

Among the figure:

1, the first mirror body; 2, the second mirror body; 3, actuating arm; 4, silicon chip pedestal; 5, alignment slot; 6, block piece; 7, bracing frame; 8, add the position in man-hour; 9, initial position; 11, the first mirror somascope face; 12, the first mirror body frame; 13, the first mirror body actuating arm; 21, the second mirror somascope face; 22, the second mirror body frame; 23, the second mirror body actuating arm; 31 first groups of actuating arm the first arms; 32, first group of actuating arm second arm; 33 second groups of actuating arm the first arms; 34, second group of actuating arm second arm; 41, upper strata; 42, bottom.

Embodiment

Further specify the technical solution of the utility model below in conjunction with accompanying drawing and by embodiment.

Be that a kind of MEMS interferes two view directions synoptic diagram of platform as shown in Figure 1 and Figure 2, it comprises silicon chip pedestal 4, the second mirror body 2, the first mirror body 1, at least one group of actuating arm 3 and block piece 6.Wherein, offer alignment slot 5 on the silicon chip pedestal 4, be placed with block piece 6 in the described alignment slot 5; One side of silicon chip pedestal 4 is connected with the second mirror body 2 by first group of actuating arm 31,32, and an adjacent side is connected with the first mirror body 1 by second group of actuating

arm

33,34.

Silicon chip pedestal 4 has upper strata 41 and bottom 42, alignment slot 5 is the rectangular recess on the upper strata 41 that is arranged on silicon chip pedestal 4, process by the semiconductor etching mode, two adjacent edges of this alignment slot 5 are arranged in the upper strata 41 of silicon chip pedestal 4 and become 90 ° of right angles, and two adjacent edges then are set to be in the same level respectively with two adjacent side of the bottom 42 of silicon chip pedestal 4 in addition; The upper strata 41 of silicon chip pedestal 4, alignment slot 5 form ledge structure with the bottom 42 of silicon chip pedestal 4.

Wherein, the first mirror body 1 is index glass or fixed mirror, and the second mirror body 2 is an index glass; Preferably, in the present embodiment, the first mirror body 1 is a fixed mirror.

(1) design of actuating arm 3

Be structural representation as shown in Figure 3, Figure 4 from the MEMS micro mirror that tilts, wherein, the second mirror body 2 is connected by first group of actuating arm 31,32 on the bottom 42 of silicon chip pedestal 4, and the described first mirror body 1 is connected on the bottom 42 of silicon chip pedestal 4 by second group of actuating

arm

33,34; And the described second mirror body 2 is vertical mutually with the plane at the described first mirror body 1 place; The deflection of the first mirror body 1 and the second mirror body 2 realizes by actuating arm 3.

Serve as reasons at least two kinds of membraneous materials of actuating arm 3 are formed, and every layer film material coefficient of thermal expansion coefficient difference; Preferably, in the present embodiment, the double-deck girder construction that actuating arm 3 is made up of two kinds of materials having different thermal expansion coefficient, in the process, it is in and adds 8 places, position in man-hour, will deflect into initial position 9 places after the release.The deflection angle of actuating arm 3 can pass through its thickness, length and width and temperature control, and as shown in Figure 5, its deflection angle θ is calculated by following formula:

θ = \frac{l_{b}}{ρ}

\frac{1}{ρ} = \frac{β_{b}}{t_{1} + t_{2}} Δϵ

Wherein, ρ is the radius-of-curvature of double-deck girder construction;

Δ ε is the poor of the temperature polar expansion that causes double layer material;

t ₁, t ₂Be respectively the thickness of membraneous material 1 and material 2;

β _bBe the coefficient of curvature of double-deck beam, can draw by following formula:

β_{b} = 6 \frac{{(1 + \frac{t_{1}}{t_{2}})}^{2}}{\frac{E_{1}^{'}}{E_{2}^{'}} \cdot \frac{t_{1}^{3}}{t_{2}^{3}} + 4 \frac{t_{1}^{2}}{t_{2}^{2}} + 6 \frac{t_{1}}{t_{2}} + 4 + {(\frac{E_{1}^{'}}{E_{2}^{'}})}^{- 1} \cdot {(\frac{t_{1}}{t_{2}})}^{- 1}}

Wherein, E ' ₁, E ' ₂Be the twin shaft elastic modulus of every kind of membraneous material, big or small elastic modulus and Poisson ratio decision by material, as shown in the formula

E_{i}^{'} = \frac{E_{i}}{1 - {&upsi;}_{i}}, i = 1,2

Wherein, E _iIt is the elastic modulus of each layer;

υ _iIt is the Poisson ratio of each layer.

Preferably, in the present embodiment, the deflection angle of actuating arm 3 is greater than 90 °.

By the aforementioned calculation angle of controlling and driving arm 3 deflections definitely.For guaranteeing that the first mirror body 1 and the second mirror body, 2 deflection rear center highly can be complementary with spectroscope, preferably, as shown in Figure 6, in the utility model, by adopting the link position of different actuating arm 3 and MEMS micro mirror, and the frame 12,22 that changes the first mirror body 1 and the second mirror body 2 adjusts the centre-height of the second mirror somascope face 21 and the first mirror somascope face 11, to be consistent with the spectroscope centre-height.

(2) design of barrier structure

Barrier structure is used to control the second mirror body 2 and the first mirror body 1 and spectroscopical relative position, as shown in Figure 7, after the first mirror body 1 and the second mirror body 2 tilt to certain angle by actuating arm 3, for guaranteeing the first mirror body 1 and the second mirror body 2 and spectroscopical vertical relation, one block piece 6 is set on silicon chip pedestal 4, its position is determined by following formula

L′=2L/π

Wherein, L is the length of actuating arm 3 double-deck girder constructions;

L ' is the length of block piece 6, and this length is counted from an end of double-deck beam; Because double-deck girder construction deflection angle is greater than 90 °, so double-deck girder construction can provide a power F to block piece 6, this power F is calculated by following formula:

F=3EIΔ/L ³

Wherein, E is the equivalent elastic modulus of double-deck girder construction;

I is the equivalenting inertia torque of double-deck girder construction;

Δ is a yaw displacement.

(3) MEMS micro-mirror structure

In the utility model, the first mirror body 1 and the second mirror body 2 all adopt the MEMS micro mirror, and its type of drive is an electrothermal drive.Be illustrated in figure 8 as the 3D structural representation of MEMS micro mirror, this micro mirror comprises minute surface 11 or 21, frame 12 or 22, actuating arm 13 or 23.As Fig. 9 is the A-A cut-open view of MEMS micro-mirror structure.

Preferably, the first mirror body 1 in the utility model and the second mirror body 2 are for teaching the MEMS micro mirror in " the An Electro thermal Tip – Tilt – Piston Micro mirror Based on Folded Dual S-Shaped Bimorphs " that delivered in 2009 with reference to the Xie Huikai of Univ Florida USA, its manufacture craft comprises the making of the second mirror body actuating arm 23 and the first mirror body actuating arm 13, the release of drives structure, the shaping of minute surface lower cavity etc.In order to improve the filling rate of minute surface, need use repeatedly deep reaction ion etching, also need positive etching to intersect simultaneously and carry out with the reverse side etching; As shown in figure 10, its making MEMS micro mirror comprises that the flow process of the first mirror body 1 and the second mirror body 2 is as follows:

(a) preparation of silicon-on-insulator;

(b) the ground floor material of the double-deck girder construction of Al() graphical;

(c) SiO ₂(second layer material of double-deck girder construction) graphical;

(d) back side silicon deep reaction ion etching (DRIE);

(e) bury SiO ₂Graphical (RIE);

(f) front silicon deep reaction ion etching (RIE);

(g) front silicon isotropic etching;

Structure when (h) being cooled to room temperature.

Know-why of the present utility model has below been described in conjunction with specific embodiments.These are described just in order to explain principle of the present utility model, and can not be interpreted as the restriction to the utility model protection domain by any way.Based on explanation herein, those skilled in the art does not need to pay performing creative labour can associate other embodiment of the present utility model, and these modes all will fall within the protection domain of the present utility model.

Claims

1. MEMS optical interference platform, it is characterized in that, described MEMS optical interference platform comprises silicon chip pedestal (4), the second mirror body (2), the first mirror body (1), at least two group actuating arms (3) and block piece (6), wherein, offer alignment slot (5) on the described silicon chip pedestal (4), described block piece (6) is arranged in the described alignment slot (5); One side of described silicon chip pedestal (4) connects the second mirror body (2) by first group of actuating arm (31,32), and an adjacent side connects the first mirror body (1) by second group of actuating arm (33,34).

2. a kind of MEMS optical interference platform according to claim 1 is characterized in that, the described first mirror body (1) is index glass or fixed mirror, and the described second mirror body (2) is an index glass.

3. a kind of MEMS optical interference platform according to claim 1, it is characterized in that, described silicon chip pedestal (4) has upper strata (41) and bottom (42), described alignment slot (5) is the rectangular recess on the upper strata (41) that is arranged on described silicon chip pedestal (4), two adjacent edges of this alignment slot (5) are arranged in the upper strata (41) of described silicon chip pedestal (4) and become 90 ° of right angles, and two adjacent edges then are set to be in the same level respectively with two adjacent side of the bottom (42) of described silicon chip pedestal (4) in addition; The upper strata (41) of described silicon chip pedestal (4), described alignment slot (5) form step structure with the bottom (42) of described silicon chip pedestal (4).

4. a kind of MEMS optical interference platform according to claim 3 is characterized in that described alignment slot (5) processes by semiconductor etching.

5. a kind of MEMS optical interference platform according to claim 1, it is characterized in that, the described first mirror body (1) is connected by second group of actuating arm (33,34) on the bottom (42) of silicon chip pedestal (4), and the described second mirror body (2) is connected on the bottom (42) of silicon chip pedestal (4) by first group of actuating arm (31,32); And the described second mirror body (2) is vertical mutually with the plane at described first mirror body (1) place.

6. a kind of MEMS optical interference platform according to claim 1 is characterized in that, the described first mirror body (1) is the MEMS micro mirror of electrothermal drive with the second mirror body (2).

7. a kind of MEMS optical interference platform according to claim 1 is characterized in that, described actuating arm (3) the double-layer films material of serving as reasons is at least formed, and every layer film material coefficient of thermal expansion coefficient difference.

8. a kind of MEMS optical interference platform according to claim 7 is characterized in that, described actuating arm (3) is a double-decker up and down, and one deck is a metal level, and another layer is an oxide skin(coating).

9. according to each described a kind of MEMS optical interference platform in the claim 1,7 and 8, it is characterized in that the deflection angle of described actuating arm (3) is by its thickness, length and width and temperature control, its maximum deflection angle is greater than 90 °.

10. a kind of MEMS optical interference platform according to claim 1 is characterized in that, described block piece (6) is spectroscope or block and spectroscopical assembly.

11. a kind of MEMS optical interference platform according to claim 6, it is characterized in that, described MEMS micro mirror comprises mirror body, frame and is connected mirror body actuating arm between mirror body and the frame, described mirror body actuating arm is the actuating arm that electrothermal method drives, and described mirror body actuating arm has and the same material layer structures of described actuating arm (3).