MACHINE SUITABLE FOR PLATING A CAVITY OF A SEMI-CONDUCTIVE OR CONDUCTIVE SUBSTRATE SUCH AS A THROUGH VIA STRUCTURE

• US 20140318975A1
• Filed: 11/19/2012
• Published: 10/30/2014
• Est. Priority Date: 11/18/2011
• Status: Active Grant

• Current Assignee: Alchimer S.A.
• Original Assignee: Alchimer S.A.
• Inventors: Raynal, Frederic
• Granted Patent: US 10,460,945 B2
• Time in Patent Office: Days
• US Class Current: 205/123
• CPC Class Codes: C23C 18/1632 Features specific for the apparatus, e.g. layout of cells and of its equipment, multiple cells
• CPC Class Codes: C23C 18/1653 Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/06 Suspending or supporting devices for articles to be coated
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/6723 comprising at least one plating chamber electroless plating apparatuses C23C, electroplating apparatuses C25D
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

The invention relates to a machine (1) adapted to metallise a cavity of a semi-conductive or conductive substrate such as a structure of the through silicon via type, according to a metallisation process comprising the steps consisting of:

a) depositing an insulating dielectric layer in the cavity,
b) depositing a barrier layer to diffusion of the filling metal,
c) filling the cavity by electrodeposition of metal, preferably copper, and
d) carrying out annealing of the substrate,
characterised in that it comprises a series of wet-processing modules (10-60) configured to conduct steps a), b) and c) by wet-processing in a chemical bath (B) and at least one additional module (70) adapted to conduct annealing step d) of the substrate (S) such that the machine (1) is capable of executing the entire metallisation process of the cavity.

Claims

1. A machine (1) adapted to metallise a cavity of a semiconductive or conductive substrate such as a structure of the through silicon via type, according to a metallisation process comprising the steps consisting of:

a) depositing an insulating dielectric layer in the cavity,

b) depositing a barrier layer to diffusion of the filling metal,

c) filling the cavity by electrodeposition of a metal, preferably copper, and

d) annealing the substrate,

characterised in that it comprises a series of wet-processing modules (10-60) configured to conduct steps a), b) and c) wet-processing in a chemical bath (B) and at least one additional module (70) adapted to conduct annealing step d) of the substrate (S), such that the machine (1) is capable of completing the entire metallisation process of the cavity.

2. The machine (1) as claimed in claim 1, in which the substrate (S) comprises an active face, on which is formed the cavity, and a rear face opposite the active face and each wet-processing module comprises a container (2) designed to contain the chemical bath (B), at the bottom (2a) of which is arranged horizontally a support (4) intended to receive the rear face of the substrate (S) such that the active face of said substrate (S) is oriented upwards in the direction opposite the bottom (2a) of the module.

3. The machine (1) as claimed in claim 2, in which the support (4) comprises arrangements to keep the substrate (S) in position during the metallisation process.

4. The machine (1) as claimed in any one of claims 2 and 3, in which the support (4) comprises protection adapted to protect the rear face of the substrate (S).

5. The machine (1) as claimed in claims 3 and 4 prises en combination, in which the arrangements and the protection are formed by at least one channel adapted to create a vacuum between the support (4) and the substrate (S).

6. The machine (1) as claimed in any one of claims 2 to 5, in which the container (2) of the wet-processing modules comprises lateral walls (2b) substantially adjacent to the support (4) so as to limit the internal volume of said container (2).

7. The machine (1) as claimed in any one of claims 1 to 6, comprising at least one annealing module (70) of the substrate (S) and in which the series of wet-processing modules comprises:

at least one pre-wetting module (10) of the substrate (S),

at least one depositing module for depositing the insulating dielectric layer (20),

at least one rinsing and drying module (60),

at least one activation module for activating the barrier layer to diffusion (30),

at least one depositing module for depositing the barrier layer to diffusion (40), and

at least one filling module for filling by electrodeposition of metal (60).

8. The machine (1) as claimed in claim 7, comprising at least six annealing modules (70) of the substrate (S) and in which the series of wet-processing modules comprises:

at least two pre-wetting modules (10) of the substrate,

at least three depositing modules for depositing the insulating dielectric layer (20),

at least one rinsing and drying module (60),

at least one activation module for activating the barrier layer to diffusion (30),

at least one depositing module for depositing the barrier layer to diffusion (40),

at least eight filling modules for filling by electrodeposition of metal (50).

9. The machine (1) as claimed in any one of claims 7 and 8, in combination with claim 2, in which the pre-wetting modules (10), depositing modules for depositing the insulating dielectric layer (20), rinsing and drying modules (60), activation modules (30), depositing modules for depositing the barrier layer to diffusion (40) and filling modules (40) each comprise means (6) adapted to vertically shift the substrate (S) between a high position, in which the support (4) is adjacent to an opening (2c) of the module (2) to allow placement of the substrate (S) on the support (4), and a low position in which the support (4) is lowered in the module (2) so as to allow its wet-processing treatment.

10. The machine (1) as claimed in any one of claims 7 to 9, in which the depositing modules for depositing the insulating dielectric layer (20), the activation modules of the barrier layer to diffusion (30), the depositing modules for depositing the barrier layer to diffusion (40) and/or the filling modules (50) further comprise a device for rinsing and drying of the substrate.

11. The machine (1) as claimed in claim 10, in which the device for rinsing and drying comprises an arm adapted to deposit rinsing fluid on the active face of the substrate.

12. The machine (1) as claimed in claim 11, in which the device for rinsing and drying further comprises a motor adapted to rotate the support (4) about a central axis of said support (4) and/or a nozzle adapted to send inert gas onto the substrate to dry the substrate (S).

13. The machine (1) as claimed in any one of claims 10 to 12, in which the depositing modules for depositing the insulating dielectric layer, the activation modules of the barrier layer to diffusion (30), the depositing modules for depositing the barrier layer to diffusion (40) and/or the filling modules (50) are arranged in a receptacle adapted to receive the rinsing fluid during rotation of the support (4).

14. The machine (1) as claimed in any one of claims 7 to 13, in which the pre-wetting modules, depositing modules for depositing the insulating dielectric layer, activation modules, depositing modules for depositing the barrier layer to diffusion and filling modules further comprise at least means adapted to enable at least partial evacuation of the chemical bath (B).

15. The machine (1) as claimed in claim 14, in which the means comprise a tube extending from a lid (3) of the module (2) adapted to at least partially aspirate the chemical bath (B), and/or a nozzle adapted to at least partially aspirate the chemical bath (B).

16. The machine (1) as claimed in any one of claims 7 to 15, further comprising a receptacle (R) adapted to receive a cassette housing a plurality of substrates, and at least one robot (80) to successively extract the substrates of the cassette and transfer them successively from one module to another to metallise at least one cavity of each of said substrates (S).

17. The machine (1) as claimed in any one of claims 7 to 16, in which each annealing module comprises:

a container (2), at the bottom (2a) of which are arranged a plate forming a cold source (71) and a plate forming a hot source (72) intended to successively receive the substrate,

an internal robot (70) configured to have the substrate move from the cold source to the hot source, and inversely, and

means adapted to replace gas prevailing in the container (2) by inert gas, and inversely.

18. The machine (1) as claimed in any one of claims 7 to 17, in which each depositing module for depositing the insulating dielectric layer comprises:

a container (2) designed to contain the chemical bath (B), here an electrolyte, at the bottom (2a) of which is arranged the support (4) configured to receive the substrate,

an anode comprising an inert metal arranged in the container (2),

lighting comprising a source emitting light beams and means for homogenising the light beams over the entire surface of the substrate so as to activate the surface of the substrate,

a power supply comprising connection means to the substrate and to the anode to polarise the surface of the substrate at an electric potential enabling electrochemical reaction, and

a sealing joint, adapted to insulate the power supply from the electrolyte.

19. The machine (1) as claimed in claim 18, in which each depositing module for depositing the insulating dielectric layer further comprises rotation means of the anode relative to the support (4).

20. The machine (1) as claimed in any one of claims 7 to 19, in which each filling module comprises a support (4) configured to receive the substrate and a motor adapted to set the support (4) in rotation about a central axis of said support (4) to evacuate part of the chemical bath (B).

21. The machine (1) as claimed in any one of claims 7 to 20, in which each filling module is further adapted to deposit on the barrier layer to diffusion a germination layer formed in the same metal as the filling layer.

22. The machine (1) as claimed in any one of claims 7 to 21, in which each filling module comprises:

a container (2) designed to contain the chemical bath (B), here an electrolyte, at the bottom (2a) of which is arranged the support (4) configured to receive the substrate,

an anode, comprising inert metal or metal identical to that which is deposited during the filling of the cavity,

a power supply comprising connection means to the barrier diffusion layer and to the anode to polarise the surface of the barrier diffusion layer at an electric potential enabling electrochemical reaction, and

a sealing joint, adapted to insulate the power supply from the electrolyte.

23. The machine (1) as claimed in claim 22, in which each filling module further comprises rotation means of the anode relative to the support (4).

24. The machine (1) as claimed in any one of claims 7 to 23, in which each activation module and/or each depositing module for depositing the barrier layer to diffusion comprises:

a container (2) designed to contain the chemical bath (B), at the bottom (2a) of which is arranged the support (4) configured to receive the substrate,

first heating, adapted to heat the substrate to a temperature of the order of 50°

C. to 80°

C., preferably 65°

C., said first heating able to be constituted by the support (4) configured to receive the substrate, and/or second heating, adapted to heat the chemical bath (B) active insertion in the container (2) to a temperature of the order of 50°

C. to 80°

C., preferably 65°

C.,

an ultrasonic or megasonic transmitter, and

a sealing joint, adapted to insulate a peripheral zone of the substrate from the chemical bath (B).

25. The machine (1) as claimed in any one of claims 7 to 24, in which each pre-wetting module comprises:

a container (2) designed to contain the chemical bath (B), here deionised water, at the bottom (2a) of which is arranged the support (4) configured to receive the substrate, and

a pump, adapted to create a vacuum in the container (2).

26. A metallisation process of a cavity of a semiconductive or conductive substrate such as a structure of the through silicon via type, comprising the steps consisting of:

a) depositing an insulating dielectric layer,

b) depositing a barrier layer to diffusion of the filling metal,

c) filling the cavity by electrodeposition of metal, preferably copper, and

d) performing annealing of the substrate,

characterised in that said steps are carried out entirely with a machine (1), as claimed in any one of claims 1 to 25.

27. The metallisation process as claimed in claim 26, characterised in that it successively comprises the following sub-steps:

(i) pre-wetting of the substrate,

(ii) deposit of an insulating dielectric layer,

(iii) rinsing and drying of the substrate,

(iv) annealing of the substrate,

(v) activation of the barrier layer to diffusion of the metal,

(vi) rinsing and drying of the substrate,

(vii) deposit of the barrier layer to diffusion of the filling metal,

(viii) rinsing and drying of the substrate,

(ix) pre-wetting of the substrate,

(x) filling of the cavity by electrodeposition of the metal,

(xi) rinsing and drying of the substrate, and

(xii) annealing of the substrate.

28. The metallisation process as claimed in claim 27, further comprising an annealing step of the substrate between the rinsing and drying step of the substrate (viii) and the pre-wetting step of the substrate (ix).

29. The metallisation process as claimed in any one of claims 27 and 28, in which the rinsing and drying steps of the substrate (iii), (vi) and/or (viii) are performed in the same module as the steps for deposit (ii), activation (v) and/or deposit (vii) respectively.

30. The metallisation process as claimed in claim 29, in which at the start of each step (i), (ii), (iv), (v), (vii), and (ix), the substrate is fixed on a support (4) arranged in the module corresponding to said step by means of a robot (80).

31. The metallisation process as claimed in claim 30, in which following fixing of the substrate on the support (4), the process further comprises a step during which the support (4) is lowered in the module and the module is closed.

32. The metallisation process as claimed in claim 31, in which on completion of each step (i), (ii), (iv), (v), (vii), and (ix), the module is opened and the support (4) is removed such that the support (4) is adjacent to the opening of the module so that the robot (80) can extract the support (4) from the module.