JPS58137256A - Insulated gate semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention is an insulated gate conductor device, with high J11! rfL
Intermodulation distortion improvement technology [@.

& Output M'08 FET As shown in Figure 1, the gap is a 2.3t N-type region formed at a distance from each other on the fitting surface of the PJl181 substrate 10, and a source and a drain. A very thin oxide film (
810m film) 4 through MO layer) Gate electrode 5t made of refractory gold lII & source.

On the surface of the substrate 81 between the drains, the 7tMfJ layers 6 and 7 are formed by forming the above-mentioned t-mask in a self-containing manner. Of this Mg2 layer, the source-N layer is the exposed N+ layer 6.
The drain 1IllN layer is made of a low-voltage breakdown layer 7 with respect to the light component. Gate 5 and N'
+ layer b a M layer 7 is covered with a thin insulating screw 8, and a layer 111 and a pole 9.10t are provided to make ohmic contact (resistance contact) with the source 2 and drain 3, respectively. The field plate 11 is formed by extending beyond the source ceramic electrode 9IIi gate and over a part of the layer 7 to increase the withstand voltage.

High power MO with 11 such field plates
In 8FIT, the field plate is a bipolar MO
It is thought that it may operate as the second gate of 87IT,
As for its output characteristics, the two-stage bending force waveform is exactly the same as that of the bipolar type MO8FICT, as shown by the symbol "-" in Figure IIz.

That is, in the - figure, (2) is a non-saturation region, which is dominated by the characteristics of the channel portion (12 in Figure 1) and the resistance of the high breakdown voltage layer (offset N layer). Source drain voltage vD8 or the point in the same figure? /l11v, &t, the channel pinches off, the current saturates, and enters the absolutely saturated field II. Up to the first saturation region, the characteristics of the channel part function as the main drain current, which is originally part of MCIIFIT. 0
It shows something close to a square-law characteristic. However, the drain voltage vD1
When r increases, the high breakdown voltage layer is pinched off by the field plate and the substrate and enters the second saturation region (2) at the boundary of point fllvDPt.

In this Ii2 saturation region, the characteristics of the high breakdown voltage layer are added to the characteristics of the channel portion, so it is thought that the characteristics deviate from the square-law characteristics.

This fellow, Breakda 9. When the voltage VBri1 is increased, the blur region becomes a blur region (9).

In this way, due to the influence of the field plate, it is possible to have a pseudo saturation characteristic region (B) t.
i deviates from the power characteristic! Since MO8FK12) engineering MD (mutual metamorphosis distortion) is large 9%, it is unfavorable.

In view of the above-mentioned points, the present invention eliminates the pseudo-saturation characteristic region t, improves the mechanical MD% property as above, and achieves a simple chest wave output MoaP
The purpose is to provide IT.

The present invention will be described in detail below along with the advantages.

MO8FET with field play 14 as mentioned above
The method to improve IMDI in K is to increase the output resistance of the 2nd saturation region (by increasing the saturated region t + flattening the saturated region part t + as shown by the broken part in Figure 2). It is considered that the square characteristic of , or the second saturation region l, should be set so that m can be waited. To increase the output resistance, (1) increase the substrate impurity -ft-. Possible measures include (2) reducing the amount of ion implantation into the high-voltage N layer, (3) reducing the amount of ion implantation directly below the field plate, and (4) increasing the field plate length. However, (1) causes a decrease in the drain breakdown voltage, (2) increases the source-drain saturation voltage and makes it vulnerable to breakdown, and (3) causes the valley 11i01. It causes an increase in I8, and (4) increases the destructive strength mo
There is a time interval between each meeting. However, there has been a need for a new structure that can improve the MDt without reducing the TTM characteristics due to the high withstand voltage.

Figure 113 shows the high frequency high output MOIiiFIT according to the present invention.
This shows the q1UA field structure.

According to the present invention v4, as a means to increase the output resistance caused by the field plate, the valley ji '
i a 11 t-field without increase, under the plate g) w & rhino T. In order to reduce the height by 1 ft, widen only the relative displacement directly below the field plate as shown in the same figure. That is, as shown in part of the process in Figs.
The drain 1iIilK high breakdown voltage N single layer 7. is formed in a self-aligned manner using this gate 5at mask. An N+ layer 6t- is formed on the source layer. (b) pH-adjusted #M8at is formed in the gas phase, and the film thickness T from the substrate surface. xl is 4000 μm, on which a second e) Mo gate 5bt is formed, (0) a new thick oxidized flL8bt type, film thickness T0 from the surface of the base 41, thickness 9000 μm. (d) Perform contact photoetch on the source and drain @2 and 3 and create a second MQ gate) 51)
A through hole is made in the oxide film 8b on top of the oxide film 8b, and a source electrode 9. is formed by vapor deposition. Drain electrode 1 (provided with a field electrode extending to the source electrode 9 at and 4) 11
'i form.

According to the structure of MO81FIT, only the oxidized aluminum JIT0 section directly under the field plate can be increased, and in that part e) the threshold voltage V t h
It will be lowered by t. It is largely dependent on the densification thickness T0 in the pseudo-saturated 111iI region described above. In this case, the European version is thinner and the part that is shifted is limited to the area directly below the field plate, and the other parts are all thicker.The reduced capacity is 0166k.
``It's not going to increase significantly.

As another means of increasing the output resistance of the second saturation limit,
As shown in Figure 1M3, P19+7z12 is attached to a part of the P-board including the channel part and directly below the field plate.
i form. In this case, the P-well impurity a degree is 5xlO
``/cd degree of purity and taX<low resistance) which is higher than that of the P-substrate.In this case, the 9th 23rd @sum voltage vP is equal to the d of the well one substrate once N1 and the high breakdown voltage N one layer (P well 1it).
It is determined by lllfN, □, and the -all-conditions voltage vDB is once '4m on the substrate where the well is formed and the well Ill! It is determined by the degree of resistance, and the withstand voltage and output resistance can be adjusted separately.

According to the present invention described in the above-mentioned implementation direction, there is no pseudo-saturation region, and the input/output becomes a square-law characteristic.

By becoming a square-law characteristic, the engineering MD% property is improved.

Figure 4 shows the input/output characteristics according to the phantom number song, and the song itself has 2
The shape of the curved edge B is larger than the square, and the curved edge B is larger than the square.

Due to such engineering and MD characteristics (C) as above, it is possible to manufacture a better IJ near amplifier according to the present invention.

The present invention can be applied to all MO1i1F]CTs for high frequency and high output, and can be applied to MOFICTKs for linear amplifiers, including those for low frequencies of 55 or less.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of one hardened high-output m08F up to tN, and Figure 2 is the current in the high-output MO8F CT.
Tortoise pressure property [Curve diagram shown, $IE3 diagram is MO according to the present invention]
87I? (Cross-sectional view showing Rihara Sanku's Seizo, Figure 514 is a logarithmized input/output characteristic curve diagram, Figure 5 +a+~ldl is MO8F according to the present invention) Knee# showing a part of the manufacturing process of Il'!' FIG.
...N layer, 7...N single layer with high withstand voltage, 8...Insulating film, 9...Source electrode, 10...Drain II pole, 1
1...Field plate, 12...P well. Figure 1, Figure 2, Figure 3, Figure 4, Figure 1,, ve,.

Claims (1)

[Claims] 1. A gate electrode is formed through a thin insulating girth on a part of the surface of the cow conductor substrate between the substrate and two conductor regions of different conductivity types, source and drain, which are formed on the surface of the cow conductor substrate at a distance from each other. A conductor layer with a different conductor from the base is formed on the surface of the conductor base between the gate and the source/drain, and a part of it is made into a 1#lt-high breakdown voltage layer, which is applied to the source/drain. In 11 fl.s. The thickness of the insulation directly under the field plate is that of the insulation layer on the high voltage withstand layer that is not under the field plate.
By making the IEk smaller than that of the high breakdown voltage layer that is not under the field plate and larger than that of the substrate that is not under the field plate, the square characteristic of the output is reduced to the region where it is saturated by the field plate. An insulated gate body device characterized by being pressurized to hold.