CN203085542U

CN203085542U - An image sensor

Info

Publication number: CN203085542U
Application number: CN 201320018126
Authority: CN
Inventors: 李平
Original assignee: 陆伟
Current assignee: Wuhan Xinxin Semiconductor Manufacturing Co Ltd
Priority date: 2013-01-14
Filing date: 2013-01-14
Publication date: 2013-07-24
Anticipated expiration: 2023-01-14

Abstract

The utility model relates to semiconductor field and specifically relates to an image sensor. The image sensor comprises a logic wafer and a device wafer which are bonded. A groove connected with metal on the top of the device wafer is disposed on the device wafer. Through holes connected with metal on the top of the logic wafer are disposed on the bottom of the groove. Metallic copper is filled in the groove and the through holes. The corners of the through holes are circular corners with large openings. When filled by using a plating manner, copper is firstly filled from the top of the groove to bottom and then is filled in the bottom of the groove, namely the openings of the through holes. Finally the copper is filled to bottom gradually. The through holes have large depth-width ratios, so filling copper in the through holes easily causes a phenomenon of premature opening sealing and generation of a hollow cavity. The corners of the through holes are designed in the circular corners with large openings so that when the groove is plated and filled with copper, the copper is not easy to accumulate at the openings. Thus generation of opening sealing and the hollow cavity is prevented.

Description

A kind of image sensor

Technical field

The utility model relates to semiconductor applications, is a kind of image sensor specifically.

Background technology

At semiconductor, image sensor field particularly, usually adopt copper plating process to interconnect, turn-on logic wafer and pixel wafer, because the depth-to-width ratio of deep trouth is big, strict to filling capacity, the image sensor of traditional structure very easily forms the cavity in the copper fill process, as Fig. 2 is transmission electron microscope (the TEM:Transmission electron microscope) schematic diagram of image sensor after filling copper of traditional structure, can obviously see the cavity is arranged in the through hole, as shown in Figure 2, and the cavity can exert an influence to the reliability of transducer, there is the space problem in the structure of tradition backside illuminated image transducer at the electro-coppering fill process, presses for solution.

Also there is not at present the image sensor of better structure can avoid generation empty in copper plating process.

The utility model content

Technical problem to be solved in the utility model provides a kind of image sensor and solves above-mentioned empty problem.

The technical scheme that the utility model solves the problems of the technologies described above is as follows: a kind of image sensor, comprise logic wafer and device wafers behind the bonding, described device wafers is provided with the groove that is connected with the device wafers top-level metallic, described channel bottom is provided with the through hole that is connected with logic wafer top-level metallic, be covered with metallic copper among described groove and the through hole, the turning of described through hole is the slick and sly turning of big opening.

The beneficial effects of the utility model are: when filling copper by plating mode, copper is down filled from the top of groove earlier, be filled into then groove the bottom, be that the opening part of through hole is filled, progressively fill downwards then, because the depth-to-width ratio value of through hole is big, fill copper-base herein and easily cause the generation of sealing phenomenon or cavity too early, the corner of described through hole is designed to the slick and sly turning of big opening, when making described groove carry out the electro-coppering filling, copper is difficult for piling up at opening part, so just can avoid sealing and empty generation.

On the basis of technique scheme, the utility model can also be done following improvement.

Further, described trench corner place is slick and sly turning.

Adopt the beneficial effect of above-mentioned further scheme to be, copper is too much piled up the filling that is unfavorable for subsequent copper at the opening part of groove, the turning of described groove is designed to slick and sly turning can prevent to fill copper by plating mode the time, at the copper of described groove opening place overheap.

Further, be provided with one deck barrier layer between copper among the described groove and the described groove.

Further, be provided with one deck barrier layer between copper among the described through hole and the described through hole.

Adopt the beneficial effect of above-mentioned two further schemes to be, copper diffusion barrier is to device wafers and logic wafer, to guarantee the quality of device.

Further, be provided with one deck bonding oxide skin(coating) between described logic wafer and the device wafers.

Adopt the beneficial effect of above-mentioned further scheme to be, make described logic wafer and described device wafers adhesive better.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

The transmission electron microscope schematic diagram that Fig. 2 fills for the traditional handicraft electro-coppering.

In the accompanying drawing, the list of parts of each label representative is as follows:

1, logic wafer, 2, device wafers, 3, groove, 4, through hole, 5, the device wafers top-level metallic, 6, logic wafer top-level metallic, 7, the turning of through hole, 8, trench corner, 9, the bonding oxide skin(coating), 10 cavities.

Embodiment

Below in conjunction with accompanying drawing principle of the present utility model and feature are described, institute gives an actual example and only is used to explain the utility model, is not to be used to limit scope of the present utility model.

Fig. 1 is a structural representation of the present utility model, as shown in Figure 1, a kind of image sensor, comprise logic wafer 1 and device wafers 2 behind the bonding, described device wafers 2 is provided with the groove 3 that is connected with device wafers top-level metallic 5, described groove 3 bottoms are provided with the through hole 4 that is connected with logic wafer top-level metallic 6, be covered with metallic copper among described groove 3 and the through hole 4, the turning 7 of described through hole 4 is the slick and sly turning of big opening, avoided copper just to seal too early preferably, promptly avoided empty generation on the top of through hole.

Described trench corner 8 is slick and sly turning, to avoid when filling copper by plating mode preventing the carrying out of subsequent copper fill process at the copper of the top of described groove overheap.

Be provided with one deck barrier layer between copper among described groove 3 and the through hole 4 and groove 3 and the through hole 4, be used for preventing that copper from diffusing to device wafers and logic wafer, to guarantee the quality of device, described barrier layer is metal nitride for example, as titanium nitride, the conductivity of titanium nitride and diffusion resistance are all better, are the better selections on barrier layer.

Be provided with one deck bonding oxide skin(coating) 9 between described logic wafer and the device wafers, described logic wafer 1 is got better with described device wafers 2 adhesions, described bonding oxide skin(coating) 9 is silica for example.

As Fig. 2 is the transmission electron microscope schematic diagram of image sensor after filling copper of traditional structure, and the image sensor of traditional structure is not slick and sly at the turning of groove, through hole, and its transmission electron microscope schematic diagram can be seen cavity 10 in the through hole.

The above only is preferred embodiment of the present utility model, and is in order to restriction the utility model, not all within spirit of the present utility model and principle, any modification of being done, is equal to replacement, improvement etc., all should be included within the protection range of the present utility model.

Claims

1. image sensor, comprise logic wafer and device wafers behind the bonding, it is characterized in that, described device wafers is provided with the groove that is connected with the device wafers top-level metallic, described channel bottom is provided with the through hole that is connected with logic wafer top-level metallic, be covered with metallic copper among described groove and the through hole, the turning of described through hole is the slick and sly turning of big opening.

2. a kind of image sensor according to claim 1 is characterized in that: described trench corner place is slick and sly turning.

3. a kind of image sensor according to claim 1 is characterized in that: be provided with one deck barrier layer between copper among the described groove and the described groove.

4. according to the arbitrary described a kind of image sensor of claim 1 to 3, it is characterized in that: be provided with one deck barrier layer between copper among the described through hole and the described through hole.

5. according to the arbitrary described a kind of image sensor of claim 1 to 3, it is characterized in that: be provided with one deck bonding oxide skin(coating) between described logic wafer and the device wafers.