JPS58101454A - Electrode for semiconductor device - Google Patents

Abstract

PURPOSE:To stabilize the ageing variation of a contactor resistance by superposing Al which contains TiN and Cu on an ohmic contact layer or a Schottky junction layer, thereby preventing a void from forming due to electromigration. CONSTITUTION:A window is opened at an SiO2 film 2 on a diffused layer 8 of an Si substrate 1, Ti 3 is sputtered in Ar, TiN 4 is superposed by a reactive sputtering method in atmosphere having Ar and N or 5:1 of pressure dividing ratio, is annealed at 450 deg.C in N2, Ti4Si3 is formed in the boundary between Si and Ti as an ohmic contact. Then, Al 7 which contains Cu is covered by a sputtering method on the TiN4. The range of containing Cu is 0.5-16wt%. According to this structure, Cu is segregated in Al grain boundary, thereby suppressing electromigration along the grain boundary. Accordingly, the production of voids can be prevented, thereby reducing the ageing variation in the contacting resistance. Since the TiN is interposed and Si diffusion is prevented from the substrate, the void in the substrate can be prevented, thereby obtaining stable electrode in large current.

Description

[Detailed description of the invention] 4-, #51 #0% Chihiro body device yc, the tube heat resistant meeting south, Ohmic contact that can be enjoyed in the great storm style exhibition or 7 yachts? The swinging meeting provides an electrode VC circle which is 0 healthy, yet has -I thermal T-, and can withstand large current savings as a Schottky swing of the first order.

At the 11th point, a machete 7 ('
l”i) or 7j is platinum silicide (PtSi) as the first
Layer 3 and (7), 2nd HIkVC-ization
N) 4. It was proposed to use aluminum (At) 5 for the third layer. 2 in the figure is the loquat layer (Bias) t
- Inappropriate〇However, even if you do this kind of 1ih formation, it will be a big deal.
When an electric current of 6 tm degrees is traced, the current flows into the
In the case shown above,
3rd layer aluminum 5 or electromicration [
As shown in FIG. 2, a void 6 is formed in the aluminum of the third stage. Due to such formation, the effective rC of the diffusion layer 8 serving as a resistor is extended, and the effective contact width is reduced.
The resistance of the contact portion increases and may change over time.

Due to this Lvc, 319th IIVC electromicration using a small aluminum lid, voids caused by the electromigration/Vc (therefore, the resistance of the contact part was reduced to 11%). stable f
! 1:' had one drawback.

17t, Another method is the third evil? As shown in the figure, the S1 substrate 1 on which eight expanded Tk layers were provided was made to contact with Sabari Real Minicum (Cu-containing A/...) 7N-koji malt to stabilize it. Due to the reaction between the Si substrate and the electromicration, the fourth
YoKhCu person 9M electric 7 electric and other i board co/tact ■W
Ninhoid 9 was formed, and this Void 9 (therefore, it had the same disadvantage as the upper Arashi Gokusei).

In 19th, I brought the Si person 9 AL electric gas into contact with the Si layer 8 to avoid the fifth damage, but a large current was generated. Ryuko and 1st 1st
Void 1 in the contact direction of 1L + jlL, l1lIll
1 is the number of ponds, and it is believed that the BIA resistance and resistance will be attractive.

For this reason, 12 in the 0-direction map where the pass #f sparrow was replaced with a spoon defect.
Use Si grains.

To this end, in order to remove these defects, 3% M
In this case, electromicration VC was used to form a core hoid using 9 AL f containing finely divided Cu. The goal is to make money.

In order to achieve the above purpose, 5 unexploded VA is made of a semiconductor substrate containing an ohmic contact layer or Schottky mating MK, a VC formed on the ohmic contact layer or Schottky mating, and a wired titanium dome and an electrified natan dome of % # distribution. The gist of the invention is to develop a semiconductor device with a copper-containing aluminum dovetail formed on top and a t-% characteristic.

Next is the implementation of Motosuke? IJ will be explained with reference to the attached drawing V. It goes without saying that the embodiments are merely illustrative, and that numerous modifications can be made without departing from the spirit of the present invention.

FIG. 6 shows the structure of the electrode of the semiconductor device of the present invention.
Figure yc lonely, 1 is Si substrate, 2 is Ii8 edge section.

3 Ti or Pt Si% 4 'I's N h
f is 0 and 9M, and 8 is the diffusion layer. With this configuration, the current of the incoming current tILvf is passed through -
%Cu people! The opposite % between JAL'l and bi & * 1
n, TiN/#4 is dyed with δiL% Cu, which has excellent electromicrition resistance, as shown in Figure 2. A stable electric current whose resistance does not change over time.
Here, Ti 3 reacts with Si by heat treatment to form titanium silicide. If the chain strength of this reaction layer or the diffusion layer that acts as an ohmic contact layer or a Schottky contact layer is not good, it will become an ohmic contact, and if the performance is low, it will become a Schottky vibration. (1) Form the IK expansion layer 8 on the K8i substrate as shown in Figure 7-) to (f) (2nd, then (b)) Insulation II on the top surface as shown in
8i 0x2 and pii! by a known method! , a contact hole 13i is formed in the marginal film 2 (see C). Next, as shown in Figure (d), Ti is formed on the upper mountain by the S/1 ivy method.
Layer 3 is placed at a pressure of 16.0 in an argon atmosphere.
8 wa Torr (/J”'F, RFF force 40
A Ti layer with a thickness of about 50 OA is formed by 0W. As shown in (e) 1c, a TiN layer 4 is formed on 'llI+3 by the two-reactive snow vine method.
j Ar: Base = 5:1 (partial pressure ratio) #surrounding pressure of 16.8 vm Torr), RF force 40
TiN pigeon 4 with a thickness of about 500^ was subjected to 0W and then annealed in N atmosphere at 450C for 10 minutes 8
As shown in the zero-order K(f) diagram, titanium silicide is formed at the interface between
A pCu-containing layer 7 is formed on the N layer 4 by a sputtering method. In this case, the ii in the % Cu-containing M is expressed by the weight S, and 0.5N-16X or mt is vhO in this case. , If the lid containing the barrel is less than 0.5X, electromicration will occur and voids will occur in the M with the shell inside the core.
For this reason, when the resistance of the contact part tends to change over time t is more than 16%, interdiffusion of the electrical material and the bonding wire material occurs in the bonding part, resulting in rc<<, and the bonding This is because there is a disadvantage that the neck layer of the part becomes abrupt.

The electrode fC of the present invention has a TiN/
The reason for selecting M with interspersed Cu is based on the following grounds. 9 per person
In the case of M, since 1 segregates at the grain boundaries of M and suppresses electromigration along the 1 grain boundaries, voids occur t
- It is possible to prevent the change in resistance of the contact portion over time.

(IIJ Cu-containing 9A1. and 81 are directly fitted and shaken. TiN serves to prevent Si from diffusing into the -1m Si substrate (with Cu)), so there are voids in 81. The noise generated can be prevented.

(Ill) Also, with Ti B ohmic contact 9
Role to make it easier T-rice table.

This is due to the above-mentioned Shioyama.

As the 8th yc Kameken, conventional yarn M/N/Ti electrode and Heiri 9AL@etc. and Cu containing 9A which is an example of the present invention.
Regarding the diffusion resistance of approximately 10Ω using L/TiN/Ti electrodes, the graph shows a comparison of time-lapse tmk when current is applied at a@degree. In this case, in the product of the present invention, 1 in M
Nonomiya 4g spear is 4 layers and 9 layers, the thickness of each floor is Cu person 9A
L layer Ja 1.5 p, TiN layer fi 500 A,
A-layer $j 500^ The 0-section test rod has a contact current of 4 x 10'A/ct, and a resistor current of 30
It's 0℃.

As is clear from this figure, it is clear that ＠l-
It can be seen that an extremely stable electrode can be obtained by replacing the third layer with 0.9 kl, which has a poor ALf electromicration resistance.

As explained above, misfire #! According to A, since the contact part is an electrode with stable resistance, it can be used as an electrode for high-power transistors and high-power ICs that are used in large quantities, and it can also be used as an electrode for high-power transistors and high-power ICs. There is an advantage that it can be used as stable ionization of LSI with high current density. In particular, the conventional 1lib'! It has the advantage of being able to be used as a stable IK resistor for high-phase diffused resistors, which require high controllability when current is applied to analog LSIs, which are used as a substitute for individual component resistors due to the pI degree. .

[Brief explanation of the drawing]

Fig. 1 shows a levered electrode, Fig. 2 shows a state in which voids are generated, Fig. 3 shows the same conventional electrode, and Fig. 4 shows a void-generated electrode. Fig. 5 also shows a conventional electrode. Figure 6 shows the electrode according to the present invention, Figures 7 (a) to (f) show its wrinkled roots, and Figure 8 shows the electrode of the present invention used in contrast to the conventional 11. lOΩ
This figure shows the time-dependent change imt in the current conduction test of the diffused resistor. 1... Silicon substrate, 2... Absolute layer,
3... Titanium layer, 4... Enriched titanium,
5...Aluminum electrode, 6...Void, 7...9AL containing copper, 8...Diffusion layer, 9...Void, lO... ...Sl containing 9 AL
, 11--void, 12...Si'B%13
・・・・・・Contact Hole Patent Applicant: Nichifu Denkiden Ayu Corporation No. 111 Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] The Schottky contact layer is included in the Ohminck-like layer and the titanium nitride layer formed on the Schottky contact layer and the excised Ohmic contact layer, and the titanium nitride layer formed on the Schottky contact layer and the circumcision Natan layer. Semiconductor device turtle 4110, which makes noises due to the increase in the number of real aluminum workers who went to Suginarijuku school.