JPH065680B2 - Manufacturing method of semiconductor device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a semiconductor device.

2. Description of the Related Art The aluminum electrodes of the contact windows of the source and drain are easily broken at the step of the insulating film. To prevent this, there is a method of melting the PSG insulating film to make the step of the contact window gentle, or a method of epitaxially growing silicon on the contact window and lifting the contact window to perform aluminum wiring.

Problems to be solved For example, if this technology of three-dimensional element is applied,
Since a high temperature of ℃ or more is required and abnormal diffusion of impurities between particles in recrystallized silicon is likely to occur, it cannot be performed. Also, melting PSG does not eliminate the step,
Epitaxial growth of the contact window also has the drawback that cavities form on the sides of the window.

Means for Solving the Problems The above problems are as follows: 1) a step of forming a field oxide film and a gate oxide film on a silicon substrate, and then removing the oxide film of a source region and a drain region using a gate electrode as a mask; A step of forming a conductive film, 3) a step of covering the conductive film located in regions corresponding to the contact windows of the source region and the drain region with a photoresist mask, and 4) etching the conductive film up to the silicon surface of the substrate. , Forming the source and drain conductive pillars and removing the photoresist mask, 5) forming a source and drain by ion implantation, and 6) forming a conductive pillar on the entire surface at the same height as the top surface of the conductive pillar. And the step of forming an oxide film, and 7) removing the oxide film on the conductive pillar by bias sputtering and removing the portion of the oxide film protruding above the gate. Planarizing by removed by, 8) and ion diffusion, and in that it comprises a step of forming an electrode on the conductive posts can be solved by method of a semiconductor device according to claim.

EXAMPLE One embodiment of a method for manufacturing a semiconductor device of the present invention will be described with reference to FIG. 1) The silicon substrate 1 was thermally oxidized to form a field oxide film 2 and a gate oxide film 3, a polysilicon film was formed on this by CVD, and this was etched to form a gate 4. As a preferred embodiment, the gate 4 was irradiated with a laser beam to melt and recrystallize the polysilicon on the surface. This is to protect the gate by increasing the etching ratio of the entire surface polysilicon and the gate polysilicon in the subsequent etching process. 2) Next, using the silicon of the gate as a mask, the oxide film in the source region and the drain region was removed. 3) Polysilicon film 5 having a thickness of 5000 to 8000Å as a conductive film
Was formed by CVD to cover the entire surface. As the conductive film, molybdenum or tungsten can be used instead of polysilicon, but in this case, recrystallization of the gate silicon is not necessary. 4) A photoresist mask 6 was provided on the polysilicon film 5 in the regions corresponding to the contact windows in the source region and the drain region. 5)
The polysilicon film 5 was subjected to reactive ion etching, and the etching was completed when the surface of the substrate 1 was reached. The gate 4 remains unetched because the surface 4'is recrystallized, and below the photoresist mask 6 the heights 5000 to 80 for the source 7 and the drain 8 are left.
The conductive column 5'of 00Å remained. The photoresist mask 6 was peeled off and removed. 6) Arsenic ions were implanted to form a source and a drain. At this time, the conductive columns 5'are also injected. If the ion implantation is performed in the step 1) as in the conventional method, the substrate silicon 1 is damaged and the etching rate is increased, and the difference in etching rate from the polysilicon film 5 is reduced. It becomes difficult to finish the etching. 7) Conductive pillar 5 '
Then, an oxide film 9 having the same height as the top surface of the conductive pillar 5'is formed by CVD on the silicon substrate 1 on which the gate 4 is mounted. At this time, a spherical oxide film 9'is also deposited on the conductive pillar 5 '. 8) The oxide film 9'on the conductive pillar 5'was removed by bias sputtering, and at the same time, the oxide film protruding above the gate was also flattened. 9) The source 7 and the drain 8 are integrated under the conductive pillar 5'by annealing. The aluminum electrode wiring 10 was formed.
Since the conductive pillars 5'and the oxide film 9 have the same height, there is no fear of disconnection.

In this example, polysilicon was deposited by CVD, but if molybdenum or tungsten is used, it can be deposited by sputtering.

According to the manufacturing method of the present invention, since the surface is flattened, three-dimensionalization of a semiconductor device can be realized with high reliability.

EFFECTS OF THE INVENTION According to the present invention, it is advantageous that the disconnection of the electrode wiring can be prevented and that the electrode wiring can be directly used for the interlayer wiring. Note that a semiconductor device can also be manufactured by a low temperature reaction.

[Brief description of drawings]

1) to 9) are process drawings showing a method for manufacturing a semiconductor device of the present invention. DESCRIPTION OF SYMBOLS 1 ... Silicon substrate, 2 ... Field oxide film, 3 ... Gate oxide film, 4 ... Gate polysilicon, 5 ... Conductive film, 5 '...
Conductive pillar, 6 ... Photoresist mask, 7 ... Drain, 8 ...
Source, 9 ... Oxide film, 9 '... Spherical oxide film, 10 ... Electrode.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Seiichiro Kawamura, 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Haruhisa Mori, 1015, Kamikodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited ( 72) Inventor Ryoichi Mukai 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Tetsuo Izawa, 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (56) Reference JP 60 -53019 (JP, A) JP-A-57-141968 (JP, A)

Claims (1)

[Claims] 1. A step of 1) forming a field oxide film and a gate oxide film on a silicon substrate, and then removing the oxide film of a source region and a drain region using a gate electrode as a mask, and 2) forming a conductive film on the entire surface. And 3) a step of covering the conductive film located in the regions corresponding to the contact windows of the source region and the drain region with a photoresist mask, and 4) etching the conductive film up to the silicon surface of the substrate to conduct the source and drain. Steps of forming pillars and removing the photoresist mask, 5) Steps of ion-implanting to form sources and drains, and 6) Steps of forming an oxide film at the same height as the top surfaces of the conductive pillars on the entire surface. And 7) a step of removing the oxide film on the conductive pillar by bias sputtering and removing a portion of the oxide film protruding above the gate to flatten the surface. Preparation of a semiconductor device which comprises the steps of: 8) and ion diffusion, and forming an electrode on the conductive pillars.