JPS5860611A - Dry etching of amorphous hydrogenated silicon - Google Patents

Abstract

PURPOSE:To achieve the selective etching of amorphous hydrogenated silicon, by carrying out the dry etching of a substrate having amorphous hydrogenated silicon coating film in a mixed gas obtained by adding nitrogen gas and hydrogen gas to a fluorocarbon gas. CONSTITUTION:An amorphous hydrogenated silicon coating film formed on the coating film of amorphous hydrogenated silicon nitride or a metal is subjected to dry etching in a mixed gas obtained by adding nitrogen gas and hydrogen gas or only nitrogen gas to a fluorocarbon gas. The fluorocarbon gas is e.g. CF4, C2F6, C3F8, etc. The amount of nitrogen gas added to the fluorocarbon gas is about 0.0001-40vol%, preferably about 0.01-3vol%, and that of hydrogen gas is about 2-40vol%, preferably about 3-25%. When only nitrogen gas is added to the fluorocarbon gas, its amount is about 0.001-45vol%, preferably about 0.01-40vol%. The pressure of the mixed gas is >=about 10Pa, preferably about 20-50Pa, and the power of electrical discharge is 20-200W, preferably about 30-150W.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to amorphous hydrogenated silicon (hereinafter referred to as [JI-8i
This article relates to the dry etching method of amorphous silicon hydrogen nitride (hereinafter referred to as "a-
8i: written as N, HJ) 11 a- provided on the metal coating
8i:) This relates to a method of selectively dry etching only the l coating.

Knee 8i:H has the following features.

1. It is a semiconductor with photoconductive properties.

2. P and N can be controlled by doping.

3. It can be laminated as a thin film, and it can also be made into a large area.

Taking advantage of this feature, the following applications are being considered and research and development is progressing.

1. Focusing on photoconductive properties and large area thin films, there are long optical sensors, solar cells, etc.

2. Focusing on switching characteristics and large area of thin film, T I
I'T (Th1n Film Transisto
r) Application to devices is affected.

When applying a-8i:H to such fields, a-8
It becomes necessary to selectively etch only the i:l coating, especially the a-8i: on the a-8i:N, H coating or the a-8i: on metal coatings such as aluminum, molybdenum or chromium.
At present, a suitable method for etching only the L film has not yet been found.

Until now, attempts have been made to apply a conventionally known silicone etching solution to Kd during buttering by etching as described above, but the present inventors' studies have shown that this method is satisfactory. It wasn't. Examples of silicon etching solutions include the following.

(a) Acidic etching solution Mixture of hydrofluoric acid, nitric acid, and acetic acid A mixture of hydrofluoric acid, nitric acid, and water, A mixture of hydrofluoric acid, hydrogen peroxide, and water, and so on.

(b) Alkaline etching liquid Potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, hydrazine, ethylenediamine, and so on.

Table 1 shows the main etching solutions and their compositions.

Table 1 Main chemical etching of 8i These silicon etching solutions are used to 8-8i:N
, a-8i on H coating: When buttering the H coating,
The following drawbacks were found.

That is, (11a-8i: N and H films are etched at the same time, (2) a-8i: H etching rate is too fast, and (3) when glass is used as the substrate, the glass is etched. Examples include.

The object of the present invention is to provide a method for selectively etching 1-8i:H which does not have the above-mentioned disadvantages.

Another object of the invention is a-8i, which does not have the above-mentioned disadvantages:
An object of the present invention is to provide a novel dry etching method for H.

Such an object of the present invention is to etch a film of a-8i:H with a predetermined pattern (19) using a fluorocarbon gas, nitrogen gas (Nx) and hydrogen gas (H3), or a fluorocarbon gas and nitrogen gas. This is achieved by dry etching in a gas mixture consisting of gas (N).
The present invention is a-8i:N.

H coating machining is an effective method for selectively etching only the a-8i:H coating provided on a metal coating such as aluminum, molybdenum or chromium.

Examples of the carbon fluoride gas used in the present invention include tetrafluor carbon gas (CCFa), hexafluor carbon gas (C, F.), and octafluor carbon gas (C, F).
, ) & can be listed.

However, in the present invention, a specific example using tetrafluorocarbon gas (CFa), which is easily available with high purity, will be described, but similar effects can be obtained with other carbon fluoride gases.

Examples of the dry etching apparatus capable of carrying out the method of the present invention include the apparatuses shown in FIGS. 1(a) and 1(b). Figure 1 (a1) is a cross-sectional view schematically showing the main parts of the dry etching I & I that can be used in the method of the present invention, and Figure 1 (b) is a cross-sectional view taken along the X-Y line in Figure 1 (a). be.

In FIG. 1(a) and FIG. 1(b), an anode electrode 12 and a cathode electrode 13 are shown facing each other inside the dry etching chamber 11. Anode electrode 1
2 has a mechanism that can adjust the distance from the cathode electrode 13, and it is generally preferable to set this distance to 10 to 100 g.

Furthermore, it is desirable that the cathode electrode 13 be water-cooled to prevent the temperature of the sample from rising while the discharge power is being applied. An annular gas introduction pipe 16 is arranged between the anode electrode 12 and the cathode electrode 13, and gas is introduced from a gas cylinder (not shown) outside the dry etching chamber 11 in the direction of the arrow, and the gas is exhausted. Gas from pipe 15 to arrow B
The structure is such that exhaust can be exhausted to an external exhaust device (not shown) along the direction of . It is preferable that the gas introduction pipe 16 is provided between the two electrodes, with its central axis substantially coinciding with the cathode electrode 13 so that a uniform gas flow rate can be obtained over the entire area between the electrodes.

A uniform gas flow rate can be achieved by arranging the gas outlet ports at equal intervals to cause the mixed gas to flow out in the direction shown by the 11 small arrows C shown in FIG. 1(b) (i.e., toward the center). It is preferable to design it so that it can be obtained,
As long as the desired conductance can be obtained and a uniform gas flow rate can be obtained over the area between the two large electrodes, the shape and size of the gas outflow, as well as the number of the gas outflows, may be appropriately selected. Then, on the cathode electrode 13,
Silicon (99,999996 purity) target plate 1
Place 4.

More specific embodiments of the dry etching apparatus that can be used in the method of the present invention are summarized as follows.

Anode electrode 12: 20mφ (made of SU8304) cuff
)'14413217+zφ (made by SIJS 304) Full area silicon target plate 14: Thickness 3, size 1
7 (mφ gas 4 (・7716...diameter of gas outlet = 1
flφ - Number of installed gas outlets = 11 pipe inner diameter: 2.5 rings ring diameter: 21 (!φ The mixed gas used in the method of the present invention is: 16 nitrogen gas 0 .0001~b is 0.O1~30%) and hydrogen gas (preferably 3~25%) is added to tetrafluorocarbon gas (CF4)2, nitrogen gas. 0.001
-45% by volume (preferably 0.01-40% by volume) of tetrafluorocarbon (CF4).

Note that the same effect can be obtained even if other carbon fluoride gas is used instead of tetrafluorocarbon gas (CF4).

First, 1. When the added nitrogen gas (Nx) in the mixed gas is less than 0.0001, selective etching of a-8i:H becomes difficult. This is undesirable because it etches the H film or metal film.

On the other hand, when nitrogen gas (N1) is added in excess of 40 volumes, the etching effect of tetrafluorocarbon (CF4) decreases, making it difficult to etch the a-8i:■1 film. There is a thing. When the added hydrogen gas in the mixed gas is less than 2 volume i%, a-8i:
Selective etching of H becomes difficult, and as a result, over-etching may undesirably etch, for example, the a-8i:N, H film or metal film. On the other hand, when hydrogen gas is added in excess of 40% by volume, the etching effect of tetrafluorocarbon gas (CFa) decreases, which may make it difficult to etch the a-8i:H film. .

That is, the gas must be a mixture of nitrogen gas (N-) and hydrogen gas (for example) and tetrafluorocarbon (CF4), which is present at the same time.

The etching photoresist pattern used in the method of the present invention can be formed, for example, by exposing a photoresist layer to a predetermined pattern and then drying it. As the photoresist, any conventionally commonly used materials can be used.

For example, as a commercially available product, the product name is 2KPR (Kodak
photo, Re5ist:=manufactured by I-Dak - developer: methylene chloride, trichlene, etc.), product name: KMh4 (Kodak Meta Etch Re
5ist' manufactured by Kodak...Developer: xylene, trichlene, etc.), product name: TPle (manufactured by Tokyo Ohka...Developer: xylene.

(Triclean, etc.), Product name: Silapray AZ'1300
(Manufactured by Shiraplay...Developer: Alkaline aqueous solution), Product name: KTFR (Kodak, Th1n FilmR
esist, made by Kodak...Developer: xylene, trichlene, etc.), Product name: FNRR (Fuji Pharmaceutical Tai...
・Current 1' liquid: chlorocene) Product name: ppgm (Fu
ji photoEtchingResist: g±
Made by photographic film...Developer: Triclean), trade name: TESHDOOL (manufactured by Kaihon Chemical Industry - developing solution: water), product name: Fujiresist Na7 (manufactured by Fuji Pharmaceutical Co., Ltd.)
--Developer: water), trade name Silapray AZ1350 (positive type) - manufactured by 7 Tsupre Ichisha Co., Ltd., and trade name OM BON-83 (negative type) - manufactured by Tokyo Ohka Kogyo ■.

Also, 2. When the added nitrogen gas in the mixed gas is less than 0.001 volume, selective etching of a-8i:H becomes difficult, and for this reason, over-etching occurs, for example, a-8i:H.
N, )l This is undesirable because it etches the film or metal film.

On the other hand, 45 volumes? If nitrogen gas is added in excess of 4'r, ol), the etching effect of tetrafluorocarbon (CF4) will be reduced, making it difficult to etch the a-8i:H film. There is.

The pressure of the mixed gas used in the present invention is a mixture of tetrafluor carbon gas (CF4), nitrogen gas (Nm), nitrogen gas (Nm), and hydrogen gas (H2). Since the selectivity changes depending on the gas mixture ratio, the magnitude of discharge power, etc., it cannot be determined exactly, but it is preferably 10 Pa (Pascal).
Above, it is particularly suitable to set the pressure to 20 Pa to 50 Pa.

Next, the above 1. Case 2. The following cases will be explained separately.

First, 1. In the case of Fig. 2(a), in a mixed gas consisting of tetrafluorocarbon gas (CF4), nitrogen gas (N2), and hydrogen gas (H2), the amount of added nitrogen gas is fixed at 0.3 volume,
The mixed gas pressure was 50 Pascal, and the discharge power was 100 Pascal.
A photoresist pattern for etching was also prepared by a dry etching method as shown in FIG.
H coating and a-8i:N.

FIG. 3 is an explanatory diagram showing the dependence on the amount of added hydrogen gas when the H film is etched separately. In the figure, 21 is a-8i:H
22 shows the change in etching rate of a-8i:N,H with respect to the amount of hydrogen gas added. In addition, the ○ mark and the 0 mark in the figure indicate the respective actual measurement values. Further, the 0 selectivity, which shows the selectivity with respect to the amount of hydrogen gas added in FIG. 2(b), can be obtained by the etching rate of a-8i:H/a-8i:N,l(etching rate). Therefore, , 23 in the figure shows the change in selectivity with respect to addition of hydrogen gas.

According to the X 2 (a) diagram and the $ 2 (b) diagram,
When using tetrafluor carbon gas containing 2 to 40 volumes of hydrogen gas, preferably 3 to 25 volumes of hydrogen gas, a
-8i:N, without etching the HvL film, a
-8i: l(a) It can be seen that the film It can be etched.

Further, although not shown, similar results can be obtained when the radiated power is set to 60 watts. However, by appropriately selecting the mixed gas pressure and kicking force, selective etching of a-8i:H is possible even outside the above-mentioned preferred numerical range.

Figures 3(a), 4(a) and 5(a) show tetrafluor carbon gas (CFa), %l, respectively.
In a mixed gas consisting of elementary gas (N) and hydrogen gas ([-1m), the added elementary gas was fixed at 0.3 volume it%, and the added hydrogen was added to tetrafluorocarbon (CiI'a). It is an explanatory diagram showing the change in etching rate with respect to the mixed gas pressure when the amount of gas added (Aoi is 5, 1 iqb, 10 volume, and 20 volume 1 iqb.
), FIG. 4(b), and FIG. 5(b) are explanatory diagrams showing the corresponding changes in selectivity.

Figure 3 (a) and Figure 3 (In figure b1, 31 is a-si when the discharge power is 100 watts:) A mixed gas of I (0.3 volume ftt = % nitrogen gas and 5 volume ftt) 32 shows the change in etching rate with respect to pressure (with added hydrogen gas), and 32 shows the change in etching rate of a-8i:N,H at this time.

33 indicates the change in selectivity calculated from the etching rate of 2441. 31', 32' and 33' are a-8i when the discharge power is 60 watts:
It shows changes in etching rate of H, a-8i:N, etching rate of H, and selectivity.

According to FIGS. 3(a) and 3(b), at a low pressure of 7 Pascals, the etching rate of if, a-8t:N,H is faster than that of a-8i:[1;
Selective etching of -8i:) is difficult.

However, if the pressure is gradually increased, aSt:N
, H decreases, resulting in an increase in selectivity. From Figure 3(b), the mixed gas pressure is 30
It can be seen that selective etching of a-8i:H can be carried out best when dry etching is performed under the conditions of Pascal, added hydrogen gas of 5 valley I1%, and discharge power of 60 watts.

In Figures 4(a) and 4(b), 41 is a mixed gas of a-8i:H (0.3% by volume of nitrogen gas and 10% by volume of hydrogen) when the discharge power is 100 Watts. 42 shows the change in etching rate with respect to pressure (with gas added), and 42 shows the change in etching rate of a-8i:N,H at this time.

43 shows the change in selectivity calculated from these two types of etching rates. Also, 41', 42' and 43
' is a-8 when the discharge power is 60 watts.
i: H etching rate 11J-, a-8i: N, H etching rate and selectivity changes.

Similarly, in FIGS. 5(a) and 5(b),
Change in etching rate with respect to pressure of a-8i:H mixed gas (nitrogen gas of O13 volume and hydrogen gas of 20 volumes) when the discharge power is 100 Watts 51. a-8i: Change in etching rate of N and H 52
It shows. Further, numeral 53 indicates the change in selectivity calculated from these etching rates. In addition, the added nitrogen gas was fixed at 0.3 volume, and the amount of hydrogen gas added was 40
Similar results were obtained when expressed as volume t%.

As can be seen from the above-mentioned inner surface, the present invention has a mixed gas pressure of 10
It is most effective when set to Pascal or higher. However, the present invention may be effective depending on other conditions even when the mixed gas pressure is 10 Pascal or less.

In addition, in the case of 2, $ 6 (Figure 11 shows tetrafluor carbon gas (CF4
) and nitrogen gas (N2), the mixed gas pressure is 30 Pa, and the discharge power is 80 W (watt).
A-8i:H film and a-8i:H film each having a photoresist pattern for etching were formed by
-8i: It is an explanatory diagram showing the dependence on the amount of added nitrogen gas when coating N and H separately; In the figure, 61 shows the change in etching rate of a-8i:H with respect to the amount of nitrogen gas added, and 62 shows the change in the etching rate of a-8i:N and H.

Note that the circles and marks in the figure indicate the respective actual measured values. Further, FIG. 6(b) shows the selectivity with respect to the amount of nitrogen gas added.

Therefore, 63 in the figure indicates the change in selectivity with respect to the amount of nitrogen gas added.

According to FIGS. 6(a) and 6(b), nitrogen gas is
．． 01 to 45 caps, preferably 0.1 to 40 t%t
It can be seen that when tetrafluorocarbon gas (cpi) to which tA is added is used, the a-8i:H film can be etched without etching the a-8i:N,H film.

Further, although not shown, similar results can be obtained when the discharge power is set to 40W.

However, by appropriately selecting the mixed gas pressure and discharge voltage, a-8
Selective etching of i:H is possible.

FIG. 7(a) is an explanatory diagram showing the change in etching rate with respect to the mixed gas pressure when nitrogen gas (N2) added to tetrafluorocarbon gas (CF4) is used in a 10-volume pot.

FIG. 7(b) is an explanatory diagram showing a change in the corresponding selection health.

Z 7 In Fig. 7(a) and Fig. 7(b), 71 indicates a mixed gas (i
72 shows the change in the etching rate with respect to the added nitrogen gas (on amount) pressure, and 72 shows the change in the etching rate of a-8i:N, H at this time.

73 shows the change in selectivity calculated from the etching speed of these two layers.

According to FIGS. 7(a) and 7(b), the etching rate of #1a-8i:N,H is a-8 at a low pressure of 7 Pa.
It is difficult to selectively etch a-8i:H, which is faster than the etching speed of i:H.

However, when the pressure is increased to the cousin a-si:N,H
Since the etching speed of the etching process decreases, the selectivity increases.

From Fig. 7(b), when dry etching is carried out under the conditions of mixed gas pressure of 30P1, added nitrogen gas of 10 volumes, and discharge voltage of 80W, a-8 is successfully etched.
It can be seen that selective etching of i:H can be performed.

In the method of the present invention, a suitable discharge power is 20 to 200 W, preferably 30 to 150 W.

Figure 8(a) shows tetrafluor carbon gas (CF4)
FIG. 2 is an explanatory diagram showing the change in etching rate with respect to discharge power when the mixed gas pressure is set to 30 Pa in a mixed gas in which the added nitrogen gas (generally) has a lO capacity.

FIG. 8(b) is an explanatory diagram showing the corresponding change in selectivity.

In FIGS. 8(a) and 8(b), 81 indicates the change in etching rate O of a-8i:H with respect to the change in discharge power, and 82! -1 a-8i at this time: This shows the change in the etching rate of N and H.

83 shows the change in selectivity calculated from these two types of etching rates.

As shown in Figure 8(a), as the discharge power increases, a-8i:H and a-
8i: The etching rate of N and H also tends to increase.

Further, as shown in FIG. 8(b), by appropriately selecting the discharge power, the etching rate distribution within the same sample can be made uniform.

For a-8i:H used in the method of the present invention, an appropriate #IE
quality can be doped. 1 For example, in the method of the present invention, a trace amount of phosphorus compound is doped to obtain 9N-
Even if you use type a-8i:)l, N-type a-8i:H obtained by doping with a trace amount of arsenic compound, or P-type a-8i:H obtained by doping with stocked boron compounds, Similar selective dry etching is possible.

Tetrafluor carbon gas (CF4) used in the present invention
There are two methods for obtaining a mixed gas consisting of nitrogen gas (N) and hydrogen gas (H2) or tetrafluorocarbon gas (CF4) and nitrogen gas (N).

1. Tetrafluorocarbon gas (CF4) K A method of mixing nitrogen gas (N, ) and hydrogen gas (H2) or nitrogen gas (N2) as additive gas in advance and introducing the mixture obliquely. In this case, tetrafluorocarbon gas (CF4) CF4) Impurities that are introduced during production are also included in the concept of the present invention.

2. A method of introducing tetrafluorocarbon gas (CF4) and additive gas (ffl* and hydrogen or nitrogen only) into a mixed gas while controlling the gas flow independently.However, in this case, if the additive gas In the case of nitrogen and hydrogen, it also includes a method in which either one is added in advance.

Also in this case, tetrafluor carbon gas (C1t'4
) Also included in the concept of the present invention are impurities that occur during manufacturing.

The effects of the method of the present invention are as follows. That is, (1) a-8i: under the coating of I-1! - as a-8i: Product IJi with a range of N and H
In the case of a structure, only the a-8i:H film can be selectively dry-etched without over-etching the a-8i:N, H film.

(2) a-8i: Aluminum as the lower layer of the H coating.

Dan 1j with molybdenum chrome or glass coating
In the case of the structure, it is necessary to selectively dry-etch only the a-8i:H film.

(3) 'r F 'I', one-piece manufacturing of long sensors or thin film TC is a must! Becomes a snake.

The present invention will be described below in accordance with the implementation sequence.

Actual column I CVI)
-8i: A film of N and H was formed. The conditions for forming the film at this time were: a mixed gas of ammonia gas and silane gas, a discharge power of 5 watts, a deposition pressure of 15 pascals, and a flow rate of i.
t 308CCM.

Next, a film of a-8i:H was formed on the film of a-8i:N and H by the same method. However, the film forming conditions are: discharge power of 5 watts and substrate temperature of 200 watts.
°C, deposition pressure 15 Pa and flow rate 308 CCM
A-8i: The use of ammonia gas used in forming the N,H film was omitted. Thereafter, in order to form a photoresist AZ-1350J (manufactured by Silabray) film on the a-8i:F film, it was applied with a spinner and dried.

Then, mist light is applied through a predetermined patterning mask,
A sample was prepared by developing a photoresist pattern for etching on the a-8i:H film.

Next, etching was performed using a dry etching apparatus shown in FIGS. 1(a) and 1(b). The etching conditions at this time were: added nitrogen gas ii 0.
Using tetrafluor carbon gas (CkY) with a volume of 14 vol. and a volume of hydrogen gas of 5 ik, the mixed gas pressure was increased to 3 vol.
0 Pascal and discharge power were set to 60 Watts. As a result, the a-8t:H film forms the desired pattern, and the a-8t:H film forms a desired pattern.
-8i: The N and H films were not over-etched.

Further, the etching photoresist did not change in quality and could be easily peeled off.

Comparative Feed Rσ The dry etching operation was repeated in the same manner as in Example 1, except that a single gas of tetrafluorocarbon (CF4) was used instead of the mixed gas used in the dry etching process in Example 1. Ta. As a result, a-
The etching speeds of the 8i:H film and the a-8i2N,H film are almost the same, and the a-8i:N,H film is overetched, and only when the etching speed is extremely slow. Although some selective etching became possible, it turned out to be completely impractical.

Example 2 Plasma CV on a glass substrate (Corning 7059)
A film of a-8i:N,H was formed by method D. The film formation conditions at this time were: a mixed gas of ammonia gas and silane gas, a discharge power of 5 W, and a deposition pressure of 1
5 Pascals and a flow rate of 30 SCCM.

Next, a film of a-8i 2H was formed on the film of a-5i:N, t (by the same method. However, the film formation conditions were as follows: discharge power was 5 W, substrate temperature was 2 watts).
00℃, deposition pressure 15 Pascal and flow rate 308C
As CM, the ammonia gas used in forming the a-8i:N,H film was omitted. After that, a-8i:H
To form a photoresist OMR-83 (manufactured by Tokyo Ohka Kogyo@) film on the film, it was applied with a spinner and dried. Thereafter, a photoresist pattern for etching was formed on the a-8i:H film by exposure through a predetermined patterning mask and development to prepare a sample.

Next, etching was performed using a dry etching apparatus shown in FIG. 1(a) and FIG. 1(b). The etching conditions at this time were to use tetrafluorocarbon gas (CF'4) with a volume of added nitrogen gas of 0.3 volume and a volume of hydrogen gas added of 10 parts, a mixed gas pressure of 50 Pascal, and a discharge power of 100 Watts. And so. As a result, a
-8i:H coating forms the desired pattern, a -8
i: The N and H films were not over-etched. Further, the photoresist for etching did not change in quality and could be easily etched.

Example 3 8i:N,H used when creating the sample of Example 1
Example 1 except that an aluminum coating was used instead of
When the dry etching operation was repeated in the same manner as in Example 1, the same results as in Example 1 were obtained regarding the etching of the a-8t:H film, and the aluminum layer was not etched at all.

Example 4 +W implementation, ylJ1. Under the same film preparation conditions as above, a-8i:N, H and a-8i:H films were formed on the glass substrate. It was coated with a spinner and dried to form a .

After that, it is exposed through a predetermined patterning mask,
A sample was prepared by developing a photoresist pattern for photoetching on the a-8i:H film.

Next, etching was performed using a dry etching apparatus shown in FIG. 1(a) and @1(b1).

The etching conditions at this time were to use tetrafluorocarbon gas (CF4) with an added nitrogen gas amount of 10 volumes, a mixed gas pressure of 30 Pa, and a discharge power of 80 W.

As a result, the a-8i:H film formed a desired pattern, and the a-si:iN,t( film) was not over-etched.

In addition, the photoresist for etching may change in quality,
I was able to let go of my depression easily.

[Brief explanation of drawings]

Figures 2(a) and 2(b) are explanatory diagrams showing the changes in the etching interval with respect to the dry etching gas pressure, Figures 3(b), 4(b) and 5. (b) is an explanatory diagram showing the change in selectivity with respect to CF4-N2-H mixed gas pressure, and Fig. 6(a) is a diagram showing the change in etching rate with respect to N1 gas field addition of CF, -N, mixed gas. FIG. 6(b) is an explanatory diagram showing the change in the selection. FIG. 7(a) is an explanatory diagram showing the change in Figure 8(b) is an explanatory diagram showing the change in selectivity, and Figure 8(a) is the
FIG. 8(b) is an explanatory diagram showing changes in etching speed with respect to h force, and FIG. 8(b) is an explanatory diagram showing changes in selectivity. O (Visual power・S5n1H Volume (%) Progress J Grain power゛Sρon Qi77 [1t (%) 5 bizorebisuυ Cattle power C Nomaska 1shi) Nbicontent power゛S Me FD (H〇Skull) Details 40-Gas E direction QXOX million C) lθ 2θ 3ρ a 9C
5th (Tonnage figure: 18FX, p7L force (RO Suff'JI'v) V crown pass Akat (7 wari rod) 6 (shi) death (勺nitnail sword pakyū 4TJ [lt<悴) 工、・Mo1; 7°'6 (A, zu-t) 5 /D Jθ 5θ; ff −@
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The power of release (w ji)

Claims (1)

[Claims] A method of etching a film made of amorphous silicon hydride using carbon fluoride gas, nitrogen gas and hydrogen gas, or nitrogen gas.