CN100505209C

CN100505209C - Method for increasing joining point strength between suspending film joining pin and substrate

Info

Publication number: CN100505209C
Application number: CNB2004100787418A
Authority: CN
Inventors: 李宗升; 邱景宏; 欧政隆
Original assignee: YOULI MICRO-SYSTEM MANUFACTURING Co Ltd
Current assignee: YOULI MICRO-SYSTEM MANUFACTURING Co Ltd
Priority date: 2004-09-15
Filing date: 2004-09-15
Publication date: 2009-06-24
Anticipated expiration: 2024-09-15
Also published as: CN1750248A

Abstract

This invention relates to a method for increasing the connecting point intensity of suspended pins and a substrate, which provides a fetch circuit chip first and forms a sacrificial layer on it, then forms an electric contact window in the sacrificial layer to expose a conduction layer of the fetch circuit chip and fills a metallic layer in the contact window to form an electric couple of the conduction film and the metallic layer, then forms an infrared sensing layer and an upper dielectric layer on the conduction film.

Description

Increase the method for the tie point intensity of suspending film pin and substrate

Technical field

The relevant a kind of method that improves infrared sensor production qualification rate of the present invention, and particularly about a kind of tie point intensity that increases suspending film pin and substrate, to increase the method for infrared sensor production qualification rate.

Background technology

Along with the quick progress of semi-conductor industry and electronic technology, the manufacturing technology of infrared sensor also is showing improvement or progress day by day.Infrared sensor not only can utilize medically, carries out the measurement of body temperature, also can be used in science, commerce and the military affairs, on purposes such as laser detection, fly bomb guiding, infrared spectrometer, remote controller, alarm, thermal imagery scouting.And infrared sensor mainly can be divided into pattern of fever (thermal) and quantum type (photon) two big classes.Because thermal infrared sensor is comparatively convenient in the use, general application is also comparatively extensive.

Generally speaking, thermal infrared sensor comprise thermocouple (thermocouple) sensor, pyroelectricity (pyroelectric) sensor, with the infrared sensor (microbol ometer) of heat resistance type.The infrared sensor of thermocouple type is thermoelectric pile (thermopile), its structure is the thermocouple of a series of polyphones, hot junction (hot junction) is arranged on the suspending film, cold junction (cold junction) then is arranged on the substrate, pin between suspending film and the substrate is essential by a series of thermocouple wire, so pin is very wide, pin is also very short usually.

The infrared sensor of heat resistance type is to utilize a slice to have high temperature coefficient of resistance (TemperatureCoefficient of Resistance; TCR) thermal sensing film is produced on it on suspending film of sensor, by at least two pins suspending film is supported on the substrate top.The thermal sensing film electrically also thus two pins be transmitted on the substrate, carry out signal by the circuit on the substrate and read and handle.The infrared sensor of burnt electric type then is to use the burnt conductive film material of a slice, is produced on the suspending film of sensing unit.The suspending film of heat resistance type and burnt electric type sensing material, all the same for its requirement of pin that is connected to substrate, basically, under the enough strong preceding topic of mechanical structure, in order to reduce thermal conductance (thermal conductance), all require pin more less, long more, narrow more, Bao Yuehao more.

Yet suspending film and pin are because the cause of technology has residual stress usually, and these stress can be oppressed structure, especially the junction point of structure.The junction point is owing to use different technology and material, and mechanical strength can be more weak, if the big intensity that too engages of stress, promptly may break in the junction point.Simultaneously, when desiring to carry out the joint of pin and substrate, the height of pin must drop to the surface of the conductive layer that reads circuit from the height of suspending film, but the conductive film on the pin is very thin, therefore forms relatively more fragile electric connection.

Summary of the invention

In above-mentioned prior art explanation, traditional infrared sensor is because pin is very big with the height fall of the conductive layer joint that reads circuit, and width and thickness with respect to pin, the length of pin is the length of ten minutes again, a little less than making that the intensity that is connected of pin and substrate is highly brittle, and then have influence on the production qualification rate of infrared sensor.

Therefore, one of purpose of the present invention provides a kind of method that increases the intensity that is connected of suspending film pin and substrate, makes the pin of lifting infrared ray sensing film and the bond strength that reads circuit in the substrate.

Another object of the present invention provides a kind of method of intensity of the tie point that increases suspending film pin and substrate, makes the production qualification rate that increases infrared sensor.

According to above-mentioned purpose, the present invention proposes a kind of method of intensity of the tie point that increases suspending film pin and substrate, the method comprises the following step, at first provide one to read circuit chip, then reading formation one sacrifice layer on the circuit chip, among this sacrifice layer, forming an electrical contact hole then and expose a conductive layer that reads circuit chip.Then a metal level is filled in electrical contact hole, and form a conductive film and metal level electrical couplings.

Then, form an infrared ray sensed layer and a upper strata dielectric layer in regular turn on conductive film.When carrying out patterning infrared ray sensed layer, keep the infrared ray sensed layer of electrical contact hole top.Simultaneously, can also when the dielectric layer of patterning upper strata, keep the upper strata dielectric layer on the infrared ray sensed layer of electrical contact hole top, with protection contact hole top infrared ray sensed layer.

Wherein, before forming above-mentioned conductive film and infrared ray sensed layer, also can form a bottom dielectric layer earlier.An etch window of upper strata dielectric layer and lower floor's dielectric layer is passed in utilization, and the etch sacrificial layer soars suspending film.And the material of above-mentioned sacrifice layer is to be polyimides, and metal level can also utilize technologies such as electrodeless plating nickel, to insert metal level among electrical contact hole.

The method of the intensity that is connected of increase suspending film pin of the present invention and substrate makes the intensity thereby the lifting of the tie point of the suspending film pin of thermal infrared sensor and substrate, and the electric connection of the tie point of pin and substrate more can be guaranteed.And utilize the infrared ray sensed layer and the upper strata dielectric layer that keep electrical contact hole top simultaneously, also can further increase the intensity of the tie point of pin and substrate.Make the infrared sensor of thermal infrared sensor, particularly heat resistance type, not only production qualification rate promotes for it, its electrical quality of more effective raising.

State with other purposes, characteristic advantage and can become apparent on the present invention for allowing, preferred embodiment of the present invention is elaborated below with reference to accompanying drawing.

Description of drawings

Fig. 1～10th is the schematic flow sheet of the method for increase suspending film pin intensity of the present invention.

Embodiment

The method of the intensity of the tie point of increase suspending film pin of the present invention and substrate, effectively improve the electrical bond strength that reads circuit in infrared ray sensing film pin and the substrate, with the mechanical strength of the tie point that increases pin and substrate, the qualification rate in the time of can improving infrared sensor production.Show that below with reference to accompanying drawing detailed description is to clearly demonstrate spirit of the present invention, as the person skilled in the art after understanding preferred embodiment of the present invention, when can be by the technology of teachings of the present invention, change and modification, it does not break away from spirit of the present invention and scope.

Fig. 1～10th is the schematic flow sheet of the method for increase suspending film pin intensity of the present invention, is that the circuit chip that reads with a thermal infrared focal plane array element is an example, and the method for increase suspending film pin intensity of the present invention is described.Consult Fig. 1, reading of thermal infrared focal plane array element forms conductive layer 10 earlier on the circuit chip, for example be aluminium, aluminum bronze or Al-Si-Cu alloy etc., and the dielectric layer 11 of circuit is read in protection.

Then consulting Fig. 2, make a sacrifice layer 21, for example is polyimides (polyimide), and this sacrifice layer 21 has a perforate 22 on conductive layer 10.Consult Fig. 3, the dielectric layer 11 of circuit is read in etching, makes perforate 22 arrive conductive layers 10, and this perforate 22 promptly forms the electrical contact hole 36 that infrared ray sensing film pin reads circuit in the substrate.Consult Fig. 4, insert a metal level 20 in electrical contact hole 36, make the height of metal level 20 contour with sacrifice layer 21 approximately.

Wherein, above-mentioned metal level 20 preferably uses electrodeless plating (electroless plating) technology, to plate layer of metal above conductive layer 10, for example is nickel, copper or other any conducting metals, makes and fills up whole electrical contact hole 36.The method of increase suspending film pin intensity of the present invention does not limit the electrodeless plating technology of using, to fill up electrical contact hole 36, any other can fill up the technology of electrical contact hole 36, for example is methods such as deposition, sputter, and it does not all break away from spirit of the present invention and scope.

Then consult Fig. 5, on sacrifice layer 21, form bottom dielectric layer 31, this bottom dielectric layer 31 also forms a perforate 51 above the electrical contact hole 36 that metal fills up.Consult Fig. 6, then make conductive film 32, as the electric connection of reading the infrared ray sensing material of circuit to the suspending film.

Consult Fig. 7, make and patterning infrared ray sensed layer 33, and keep the material that is plated in the infrared ray sensed layer 33 on the electrical contact hole 36.Consult Fig. 8, form upper strata dielectric layer 34, with the infrared ray sensing material in the protection infrared ray sensed layer 33.Consult Fig. 9, define the zone of suspending film and pin, and open the etch window 35 of sacrifice layer 21.Then consult Figure 10, to etch away sacrifice layer 21, make suspending film pin 30 unsettled by etch window 35.Wherein, suspending film pin 30 can be finished the electrical couplings that reads circuit and conductive film 32 owing to only need to contact with metal level 20.Therefore, conductive film 32 need not go deep in the electrical contact hole 36, directly contacts with conductive layer 10.Therefore, the intensity of suspending film pin 30 thereby lifting, and more help to guarantee electrical connection quality.

In the making of existing thermal infrared focal plane array element, all can make on chip earlier usually and read circuit, there is the dielectric layer protection on this top layer of reading circuit, has the micro electromechanical structure of making the infrared ray sensing on the chip substrate that reads circuit then.At first be to read making one sacrifice layer on the circuit, and in this sacrifice layer and substrate, formation one electrical contact hole expose the conductive layer that reads circuit in the substrate to the open air.But, because electrically the thickness of the depth ratio conductive film of contact hole is a lot of greatly, cause conductive film must go deep among the electrical contact hole, it will cause electrically contacting the reduction of qualification rate, and the mechanical strength of conductive film is reduced.

In order to overcome above-mentioned shortcoming, the method for the intensity of the tie point of increase suspending film pin of the present invention and substrate before making conductive film, electrically inserting a metal level in the contact hole, for example is to form this metal level with electrodeless plating promptly.This metal level generally is about 2 μ m, and material for example is a nickel, will fill up whole electrical contact hole, and connects the conductive layer that exposes to the open air out in the substrate.The suspending film pin and the electric connection of reading circuit are named a person for a particular job and effectively are increased to the top of electrical contact hole then, not only make the mechanical structure of tie point of pin and substrate strengthen, and also can guarantee electrical connection.

The sensing material of the infrared sensor of heat resistance type is generally barium oxide (VOx), via this barium oxide of etching to form the infrared ray sensing film.The method that the present invention increases suspending film pin intensity also keeps the heat resistance type sensing material on the tie point of pin and substrate, therefore, and about 600

^-900

Conductive film on, add about 1k

The heat resistance type sensing material of conduction, the electric connection of the tie point of pin and substrate more can be guaranteed, and the mechanical structure of the tie point of pin and substrate also can further be strengthened.The present invention also can keep the upper strata dielectric layer of tie point top, protects the heat resistance type sensing material that keeps on the one hand, further strengthens the mechanical structure of the tie point of pin and substrate.

Though the present invention discloses as above with a preferred embodiment; yet it is not in order to limit the present invention; any ripe be present technique personnel without departing from the spirit and scope of the present invention; when the change that can do various equivalences or replacement, so protection scope of the present invention is when looking accompanying being as the criterion that the application's claim scope defined.

Claims

1. the method for the intensity of a tie point that increases suspending film pin and substrate comprises at least:

Provide one to read circuit chip;

Forming a sacrifice layer reads on the circuit chip in this;

Form an electrical contact hole among this sacrifice layer, to expose the conductive layer that this reads circuit chip;

Insert a metal level among this electrical contact hole;

Form a bottom dielectric layer;

Form a conductive film and this metal level electrical couplings;

Form an infrared ray sensed layer on this conductive film;

This infrared ray sensed layer of patterning, and keep this infrared ray sensed layer of this electrical contact hole top;

Form a upper strata dielectric layer on this infrared ray sensed layer;

This upper strata dielectric layer of patterning, and keep this upper strata dielectric layer of this infrared ray sensed layer top of this electrical contact hole top;

Form an etch window among this upper strata dielectric layer and this bottom dielectric layer, and expose this sacrifice layer; And

By this etch window, with this sacrifice layer of etching.

2. the method for claim 1, the material that it is characterized in that described sacrifice layer is a polyimides.

3. the method for claim 1 is characterized in that the described step of inserting a metal level is to utilize electrodeless plating to insert this metal level.

4. method as claimed in claim 3 is characterized in that described metal level is a nickel.

5. the method for claim 1 is characterized in that it being to be used to make a thermal infrared sensor.

6. method as claimed in claim 5 is characterized in that described thermal infrared sensor is the infrared sensor of a heat resistance type.

7. the method for the intensity of the tie point of suspending film pin that increases infrared sensor and substrate comprises at least:

Provide one to read circuit chip, and this read circuit chip and is protected by a dielectric layer;

Forming a sacrifice layer reads on the circuit chip in this;

Form an electrical contact hole among this sacrifice layer and this dielectric layer, to expose the conductive layer that this reads circuit chip;

Insert a metal level among this electrical contact hole;

Form a bottom dielectric layer;

Form a conductive film and this metal level electrical couplings;

Form an infrared ray sensed layer on this conductive film;

Form a upper strata dielectric layer on this infrared ray sensed layer, to protect this infrared ray sensed layer;

By this etch window, with this sacrifice layer of etching.

8. method as claimed in claim 7 is characterized in that the described step of inserting a metal level is to utilize the method for electrodeless plating to insert this metal level.

9. method as claimed in claim 8 is characterized in that described metal level is a nickel.

10. method as claimed in claim 7 is characterized in that described infrared sensor is the infrared sensor of a heat resistance type.