JPS59150430A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a highly reliable device having an amorphous thin film which shows fantastically low polarizability and has no shift of C-V curve with a leak characteristic of about 10<-12>-10<-10>A by providing said amorphous thin film having a particular molpolarizability in contact with the upper or lower part of metal wiring of a single or more layers. CONSTITUTION:An amorphous thin film having mol polarizability of 0.007-1.00 is provided in contact with upper or lower part of a single layer or more layers of aluminium wirings of MOS device. The mol polarizability of film is set to 0.007-1.00 because if it is 0.07 or less, glass cannot be obtained by ordinary oxide material. When it becomes 1.00 or more, the C-V curve of device shifts toward the high gete voltage side and a leak current also increases. Accordingly, the device characteristic is drasticaly deteriorated. An amorphous film may be formed by any amorphous film forming method including sputtering, electrophoresis method, vacuum-deposition, dipping into the suspension, and reflow method, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a low leakage current, highly reliable semiconductor device using a low polarizability amorphous thin film as a protective film.

[Prior art and its problems]

In the conventional technology, the A
PbO glass was used above or below the l wiring. PbO glass has the advantage of being fluidized and flattened at low temperatures, but the molar polarizability of Pb4+ is as high as 1.56.
Using this for passivation, the characteristic C--curve of a device fabricated with 1<7 began to shift toward the high gate voltage side, and the leakage characteristics deteriorated/ζ, causing problems in use.

[Purpose of the invention]

The present invention was made to improve these drawbacks, and its purpose is to reduce the polarizability of the conventional PbO glass, although it is much lower than that of conventional PbO glass, and to improve the C-■ curve of the fabricated device. There is no shift and the leakage characteristics are 10-
The object of the present invention is to provide a highly reliable device equipped with an amorphous thin film capable of obtaining a power of about 12 to 10-10A.

[Summary of the invention]

The present invention is a MOS device characterized in that an amorphous thin film having a molar polarizability of 0.007 to 1.00 is provided on or below one or more layers of Al wiring. The reason why the molar polarizability of the membrane is limited to 0.007 to 1.00 is 0.0
This is because if it is less than 7, glass cannot be formed with ordinary oxides, and if it is more than i, oo, the C-■ curve of the device will shift to the high gate voltage side, and the leakage current will increase, causing the device characteristics to deteriorate significantly. This is because it will get worse. The amorphous film may be formed by sputtering, electrophoresis, vapor deposition, suspended liquid immersion, reflow, or any other method for forming an amorphous film.

〔Effect of the invention〕

For example, if the molar polarizability of the glass is 0.007 to 100 on the P-channel'A1gate polysilicon FET,
A device with a protective film of about 0.5μ thick was fabricated using a thin film of glass using a sputtering method, and the T characteristics were examined. The C-■ characteristics showed a normal curve, indicating that the device/7
)IJ-ri...1st class is... -11A, and the field effect hole mobility was 80 to 100 m/V·see.

[Embodiments of the Invention] FIG. 1 shows a device cross section of the P-channel Ag gate polysilicon FET. 1 is S+ wafer ([10), 2 is 5i02 It@, B is positive silicon↓・4 is All,) 51[is 7・Galila Inc., 7
4 membranes 1, 86 U *1. , lzu-5・7-・
7, S, io, 2 films 1-8), yield 1, oxidation, knee, 91 is the p-type region. The glass film was deposited to a thickness of 0.5 μm by sputtering. Next, the characteristics of these devices will be described with reference to examples.

(Example 1) B2O370mo1% GeO220mo1 as a protective film of the P-channel polygy-si device
A glass coating having a composition of 1% SiO2, 1% Mg05mol and 1% Mg05 was deposited to a thickness of about 0.5μ by sputtering. The molar polarizability of the glass was 0.45. Laser annealing or thin melting method was used to grow poly-st grains. P with protective film
-The enhancement type field effect hole mobility of channeleeFET is 907/v*sec leakage current 1
0A, CV characteristics were normal.

(Example 2) As a protective film of the P-channel poly-si device, B2O365mai1%So0210mO1%
, P2O55mol, Zn015mol1%, Be05
A glass film with a composition of mod% is 0.5μ by sputtering.
It was deposited to a thickness of .

The molar polarizability of this glass was 0.38. paly
The zone melt method was used to grow the -si grains. F″ET enhancer with protective film
T-type field effect hole mobility is 95cn/v-see
The J-current was 10-10A, and the C-V characteristics were normal.

(Example 3) B203 70 mar2%, Si0225 ma
A glass containing 1% BaO5rnol was sputtered to a thickness of 0.5 μm over the device as a protective film. The molar polarizability of the glass was 0.46. The field effect hole mobility of the enhancement type FET with a protective film is 80 d/v'sec 1 The leakage current is 1
o-10A-1c-v characteristics were normal. In addition, the c-■ characteristics of the devices of each example are shown in curves 1 to 1 in Figure 2.
3, and an example of PbO glass as a comparative example (curve 4)
showed that.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of an MO8 semiconductor device, and FIG. 2 is a curve diagram showing the C-■ characteristic according to the present invention. 1-8t') xha(10°Q,), 2-8'102
(3000X) membrane, 3-poly=Si(0,7μ
) film, 4-Al film, 5... glass protective film. (7317) Agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1

Claims (1)

[Claims] The molar polarizability is 0. (A semiconductor device characterized in that an amorphous thin film of JO 7 to 1.00 is provided in contact with the upper part or part of one or more layers of metal wiring.