JPS6288370A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent deterioration in characteristics of an FET, then ions are implanted through an insulating film, which is formed on the side wall of a protruded part, by preventing the projection of an ion beam on a heterojunction interface between a GaAs layer and an AlGaAs layer. CONSTITUTION:A pattern of a high-melting-point metal gate 6 of Mo and the like is formed. With this pattern as a mask, an N-type AlyGa1-yAs layer 4 and a non-doped AlxGa1-xAs layer 3 are selectively removed. Thus, a protruded part, which is to become a gate, is formed on the surface of a semi-insulating GaAs substrate 1. Then, an insulating film 11 is deposited on the entire surface. The insulating film 11 is etched with directivity being provided from the direction, which is vertical with respect to the surface of the substrate, by reactive ion etching using CF4. Then, the insulating film 11 is made to remain only on the side wall of the protruded part. With the protruded part and the insulating film 11 formed on the side wall of the protruded part as masks, ions are selectively implanted in the source and drain regions of an FET. S ions are used for the ion implantation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a field effect transistor using a selectively doped semiconductor heterojunction.

Conventional technology N type A%! A high-speed field-effect transistor (FET) has been fabricated using a highly mobile two-dimensional electron gas that accumulates at the heterojunction interface between LAS and GaAs, and is called a high-electron mobility transistor (HEMT). ing. This type of transistor usually has an N-type A7+ on the G115 layer.
A two-dimensional electron gas and electrode contact are formed through the GaAS layer, but the N-type A/GaAs and electrode metal A
Since the contact resistance with uGe/Ni/Au is relatively large, a problem has been considered that the device performance cannot be fully demonstrated.

One way to solve this problem has traditionally been to
/GaAs layer k; 1'f 41<, 4:
# For those who want to know - Gaps layer has 11 force methods 6eC] 2, Fig. 2 II (, Iftl L-Cit Song method ('i1゛J, below in cylinder,]・1('＼Ro1゜In Figure 2 (?L), 1Q-1 lower insulation 1/1CTaAs;
l, t: plate, 2C[nondo-1GaAS layer, 3&:
inondo7'J) (GajXAS layer, 4 is N type A 5
yGa 1-, yAS layer (HaA/GaAs layer 3 and non-beef-GaAs layer 2 (+') ”-fj L-1
@ Combine 11, 'tfii (/(-, 2-dimensional electron gas 6
is formed Jl, is, 2 this 11 (temporary stand - month 1 and 1
Example lrM"fc Tono height t, 6', l!, 1,'
, ■ Gold FM', f-16 (1'-) pattern shaped 1j
lj l-,, and further N-type Af! yG2L+ -yAs
Layer 4 and non-doped A, /) (Ga 1-, XA 8
Layer 3 is high secondary (point 4/select gate pattern as mask IJ
(2.11) (2.11) Form a convex base on the board surface. Using a mask 17, selectively inject 114 ions of ion tTE into the source/drain formation region. 3. Figure 2(b) shows an ion beam of 11 people with J, 7t, and 1I, and the ion beam of 11 people is, for example, 70Ke.
28S1 with an acceleration energy of V ~ 160KeV, (1X10. using an ax, "', hundreds of Bg six mice in a bunch. 8
Q-4 ion/one person/ζ region is shown. (After 7 days,
For example, 850' (:.

1o1:'t・~20u'fni') A:-・-r, A
s shield 4 circles in air 7 inactive 1 cow scum atmosphere “Cf'i
Now, there are 71 people.
hfi s or form tJi σノ1/). 1,7 Karushun,
AuG3 /Ni Au from Au-Mic City, Pole 10 to y1 Seo Sei 1. , 'FIT was created).

Invent or solve. l、One problem It i:(7) 'Jjr-7k ``'l': Between j
i! -rl Tona/,) Tsuba, ffi 2 M (b)
If (, L- is 0 mark and small-7 (A's territory; Bodokoro 1
11j (Acor--L) body! 7. ! , 3, which is a surface state, JGaAs l! -: GaAs (7)! 4% and 1i1h of Sl: 'i': 冑 Agriculture f-]nl(-
When I went to 1 iJ of heat treatment without 4 people, I got A/+.
1-Ga II expansion 1) or iL L:, ,'+Y
It is generally known that an AgGaAs layer with a small cell ratio of AlAs is formed in Ifii (iH). 11
-) in Fig. 2(b) c7) In the A region, GaA
The j and +ij planes of S and AgGaAs are steep (19-Ci:
(iS, non-doped GaAs layer 2)
AjGaAS is formed on il. If this is the case, then subtract the lower value of the secondary nine-electron gas V) in region A/agricultural rate and activity...1.・So, 33fn-, which will be a gift of resistance in this area, is F.
2. The source resistance of the ET increases, and the device characteristics deteriorate. .

The present invention is based on the conventional 1-CtIl', solid 4) AgGa
The interface between the As layer and the GaAs layer is irradiated with an ion beam.
Heat treatment caused by 'lruko, ,] f: 1+++', y
7= r7tc : t==Keru Ae and Cr a (1
) 1117j It is intended to eliminate the diffusion and reduce the deterioration of the raw r4/I to the direct weight L7.

Means for solving the problem /ξ, l/) The present invention is directed to the ion implantation r during formation of the source/drain region.
+4. : At this time, the ion beam is irradiated onto the W surface from A (!interface 4 between the GaAS layers and the insulating film) -VC.

The action of this ``secondary unexploded fill'' method is to use the insulating film that covers the LW surface.
It is possible to prevent IL from being irradiated with the beam, and the element 'l'jr
The deterioration of l'l- can be directly affected.

Embodiment An embodiment of the present invention is explained in detail in Figure 1 (C).
aAs substrate, 2 has a II% thickness of 0.6 to 1.071 m (
7) Non-doped GaAs layer, 6'\-3 is non-doped At with a film thickness of O~3oO! xGa,
.

As layer, 4 is N Jf Ni A, 1yGa1. The As layer is A/! xGa, -XAsAs layer non-doped Ga
A two-dimensional electron gas 5 or 114 is formed on the W plane of the As layer 2.
I'm here. Similarly to the conventional method, a pattern of 1 (+lJ, i, high melting point metal gate such as Mo (J, q), F margin) 6': c is formed, and this pattern %knee, 71
As a ward, N type A7! yG Town-y A, 3rd floor 41.・
1! and 2 no'-1-A /) (Ga 1.,,,XA
S layer 3 '+: i,'! ': J) Kuniyuki no, 17
, no+<, convex r'+lI k with game 1 on the 7th side
: Ishi1戊-J/).

Next, the film i) 7: 'Ha 1600 to 13000 for all songs
Human 1m41 Membrane 114 treatment ii″: Sui) (!″1′3
Figure 1 (bi 'II, &/! Membrane 11J-)
5102 film, Si3N4 film, etc. were used. (Afterwards,
The insulating film 11 is made of CF4 reactor j-, e] f oni, -1
-Notinku (/(2, 17su, 11
Junior High 1 Hakuotsu: Nono Muki 31 with direction f1 +, "T -
(':”:y 4ink?r ■i), leaving an absolute ft1lP 1i only on the side wall of the convex part (2, I- comes., ζ- convex part, ll1 mouth rl (1ill 11. '
? The insulating film 11 formed on the FET is used as a mask.
Selective ion implantation into the source/domain region of ri:
f"'r h, U3. Figure 1 (C) 4(-,
7U1 ion Ehito's fonpi J. is small (,te'',・su, 8Q-1 ion Ehito area is small.Ion 11-person (〆1.70 K6V ~ 16oKeV! River Rinaka Energy
G-C8 (sulfur ゛()-i A-in included・1＼1014
Dance 7 [Reason for using t1f,,oS,,r-on in 1+ (,1, t+- annealing after human causes diffusion of S, -next]■, electric gas and N- '(jrl
F4-'I's 12, continued (1, ni ``reke, guichi?''
J /
i': ,ll,d)-',? :Nishishi? [J1 Gas 6 and N1 Region 1'l) 1 Hinisuke: i, :) Kai,)
1 without -J Mukara 4+3. ,,(-Ant + Ben's Io, God and 1. Use S and Sl at the same time - CN area's blood-rear i!'+'k W k-,) t7 search c, 1-also river RL-C 0, 1'on L1 person later, A
+ (su1 bury (anini・) L)'tr: Porta-7”
Ianhaan I-5, s D'J [r < t /
This is the SJ Si process ()4 electrically 211'l-4:!71., and at the same time the SJ Si'c 11m dispersion-J (iN') GaAs layer 9 is formed 1-2. .14 Second brother 71 Terekasu 6 clN"' connect the area, -1, (
Figure 1 Ld) ) t+6 (b: AuGe, /
10 pieces of NiAu electrode are formed and the 1st (e) FET is made with 4 pieces of 2 sinter.
J d 7'L Z) (Figure 1 (0).

1P [-The main point of the example is gate J-A) Forming an insulating film on the side wall of the convex part 1-8, Ion L-1 person's 1-history light Q,
Iji-1 is a heterojunction between GaAS layer, JJGaA, and s layer! ifi'', 1°) not on the surface, 1, sea urchin, 3y, H on the implanted ions, secondary 1-4 electrician scum (Ant1, formed by humans) during heat treatment. NG
The aA, s region is defined as S (4? using yellow direction diffusion), and the heat treatment force θ and the refractory metal layer are added to 1 (l・Chang i! Intervention is 7+ ', 17).

1 This Example 1 + A77 GaAs layer jJ! AS'
(Le I:b, X and yQ-1I[,0,2x,y
-0.8 range in January 11). In the example, ij N-/
As mentioned above about Jannel's FET, the same applies to P-channel I/A, and in this case, Be or Be is used as an impurity.

-Also, -1 mentioned 17/(one example-rh(, t-in-den-t14 people's in-density), S-ion, /l'>”d: l-11 not In this case, it can also be carried out by adding Sj by substituting Sj as shown below. Quantity l retsuka 1″〕1C year old, 9
During the heat treatment after 1711 hours, the pure impurities spread into the GaAs layer, causing the N-type GaAs layer to form a convex portion 1.
111 Under the wall CraA, SF (shape IJk in j minute /
), so it, ti + difficult to do $1 Imen is ion l-1
Although it is used for human ion expansion, four-dimensional electron-f gas and N''Ga
4. The As layer is in contact with U1.

For the coupling of the P-channel FET, add Zn in the insulation layer 11 (just enough).

Effects of the Invention In the present invention, 1': fl, rJ: Due to the insulating film formed on the side wall of the convex portion, heat is generated on the p2 of the GaAs layer and the A6GaAs layer on the heprojunction W surface of the GaAs layer and the A6GaAs layer. I! ((, fl, t can be done 17+ months)), the 7 degrees and mobility of the 12-dimensional electric current at both ends of the convex part due to the heat treatment J's beating after ion treatment. 3. It is possible to suppress the 71!J characteristic of the FET.

[Brief explanation of drawings]

Figure 1 (1; 1 Method of manufacturing a semiconductor device 11 according to an embodiment of the present invention 4-Explanation 2) Cross-sectional view of the culm, Figure 2 is a conventional manufacturing method. Under 1.Ji
1 is a sectional view. , 1...) 1' insulation (/l GaAs-t, plate, 2... non-doped □eaAs layer, 3-=-non-doped' A 1xGa j-, XAS layer, 4... N-type A/+yGa1yA 8 layers, 6...--dimensional electric f gas, 6... Sieve melting point metal gate electrode, 7...
Ion beam, 8... Ion t [large area, 9...
...NGaAs layer, 10... Ohmic electrode, 1
1... Absolute E* membrane. Agent Mr. 1 -4v Riji 1 Masao Nakao (・
-J or 1 person Figure 1 Figure 2

Claims (2)

[Claims] (1) A non-doped Al_xGa_1_-_xAS layer with a film thickness of 0 to 300 Å on the GaAs layer and a first conductivity type A
forming a high melting point metal gate electrode on the surface of a semiconductor substrate having a structure in which l_yGa_1___yAs layers are sequentially formed; and using the high melting point metal gate electrode as a mask, the undoped Al_x is applied from the surface of the semiconductor substrate.
A step of selectively removing up to the Ga_1_-_xAs layer to form a convex portion, and after depositing an insulating film on the entire surface, removing the insulating film by dry etching from a direction perpendicular to the surface of the semiconductor substrate, a step of leaving the insulating film only on the sidewalls of the convex portion; and using the convex portion and the insulating film formed on the sidewalls of the convex portion as a mask, selectively adding impurities of the first conductivity type to the source/drain forming region; After ion implantation,
A method for manufacturing a semiconductor device including a step of performing heat treatment. (2) A method for manufacturing a semiconductor device according to claim 1, wherein an impurity of a first conductivity type is added to the insulating film.