JPS58176928A - Light annealing - Google Patents

Abstract

PURPOSE:To restrain deformation (warpage) of a processed substrate by a method wherein anneal processing is performed with flat plates made of light-permeable material being held into pressure contact with overall surfaces of the processed substrate. CONSTITUTION:A processed substrate 5 is held between flat plates transparent for infrared rays, e.g., quartz glass flat plates 6a, 6b with a thickness of approx. 5mm.. Pressing means 7 such as springs are used to cause these glass flat plates to come into pressure contact with the overall surfaces of the processed substrate 5 on both sides thereof. The processed substrate 5 is fixed through support means 8 onto a stage 4 in an anneal furnace of infrared radiation type such that the main plane (the plane having a polycrystalline Si layer formed thereon) of the substrate 5 is directed toward a first infrared lamp 1a having a function to focus an infrared ray. While moving the substrate at a given speed between both first and second infrared lamps 1a, 1b, it is scanned with an infrared beam to locally gradually melt the polycrystalline Si layer, so that the polycrystalline Si layer is single-crystalized by degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a light beam annealing method using a light radiation annealing furnace, and more particularly to a light annealing method for a flat substrate to be processed such as a semiconductor substrate.

(b) Background of the technology In the manufacturing process of semiconductor devices, infrared radiation is used during high-temperature short-time annealing or local annealing such as activation of ion implantation regions or single crystallization of polycrystalline silicon layers. An annealing method using heating is used◎ (c) Conventional technology and problems For example, 5Oxs (s...con On Inmulat1
In the manufacturing process of ng8ubstrat@), when forming a single crystal 81 layer that will serve as a base for forming active elements on an insulating film formed on a silicon (81) substrate, vapor phase growth was performed on the insulating film. A method is used in which the polycrystalline '81 layer is scanned with a bell-shaped infrared beam and localized to KM-order SS to form a single crystal layer.It is also used to form a specific functional area in a semiconductor device. During this process, impurity ions are selectively implanted into the surface of the conductor substrate, and the surface of the semiconductor substrate is heated for example at 1000 nm in an infrared radiant annealing furnace as shown schematically in the horizontal section of 11 layers in Figure 1. (”c) @ 1
When the ion-implanted region is activated by heating for a short period of time (seconds), the ion-implanted region can be heated to minimize the effect on other functional regions that have already been placed on the skeleton semiconductor substrate, thereby achieving a specific function. There is a method to form an area.111aii
In lK, 1 is a rod-shaped infrared lamp, 2 is a reflecting mirror, 3 is a semiconductor substrate, and L is infrared.

However, in these conventional methods, only the semiconductor device was heated by radiant infrared rays while it was placed flat or upright on the stage.
Large deformations that may cause problems in subsequent manufacturing processes (for example, cracks in the semiconductor substrate during the contact exposure process, defocusing during the projection exposure process, etc.) occur, and the manufacturing yield of semiconductor devices decreases. There was a problem that performance deteriorated.

(d) Purpose of the invention It is possible to provide a solution and eliminate the above problems.

(・) Structure of the Invention That is, the present invention provides a method for applying high-temperature, short-time annealing treatment including local annealing to a flat substrate to be processed using a light beam annealing furnace. 〇(f) Embodiments of the Invention The present invention will be described in detail below with reference to the drawings in terms of embodiments.

FIG. 2 is a schematic horizontal cross-sectional view of one embodiment 91 of the present invention (
A) and A-A' vertical cross-sectional schematic diagram (B), and FIG. 3 is a vertical cross-sectional schematic diagram (A) and A-A' vertical cross-sectional schematic diagram in another embodiment of the present invention. (b).

For example, when monocrystallizing the polycrystalline 81 layer in the 80IS manufacturing process using the method of the present invention,! As shown in Figures 2) and (b), the first reflecting mirror 2 has the function of forming an infrared ML that focuses linearly on the surface to be scanned.
A rod-shaped Ill infrared lamp 1a equipped with a lamp and a rod-shaped second infrared lamp 1b equipped with an IE20 reflector 2b having a function of forming parallel infrared ML perpendicular to the irradiated surface face each other. An infrared radiant annealing furnace is used in which a stage 4 movable in the left and right direction is provided between these infrared lamps. Also, as a substrate to be processed for forming the 80IS base plate,
For example, silicon dioxide (Slow) II of about 1 [μm] is formed on the surface of a 5 [inch] diameter Si substrate by a method such as thermal oxidation, and then silicon dioxide (Slow) II, for example, 0.5 [μm] thick is formed on it by a vapor phase growth method.
A polycrystalline 81 layer with a thickness of about 0.5 to 1 [μm] is formed on top of the polycrystalline 81 layer with a thickness of about 0.5 to 1 [μm].
Silicon nitride (SisNa) of about 1 to 0.2 [μm]
In the method of the present invention, the method shown in FIGS. 112 (a) and (b) is used.
As shown in K, the substrate 5 to be processed is exposed to infrared #! A transparent flat plate 1, for example, a thick quartz glass plate 6m, 6b, with a thickness of about 5 [■] is held between both sides, and the glass flat plate is pressed against the substrate by a pressure means 7 made of a spring or the like. 5. Clamp with quartz glass sheets 6a and 6b while pressing the entire surface. 1 on stage 4 in the infrared-radiation annealing furnace.
, the main surface of the target group @ 5 (polycrystal 81
The first lens has the function of focusing on the surface (on which the layer is formed).
Infrared lamp 1 & fix it facing negative. Next, the substrate 5 to be processed, together with the stage 4, is moved at a predetermined speed between the Ks11!1, the second infrared rays, and the lamp 11.degree.1b. For this! The parallel infrared MILK radiated through the reflecting mirror 2b of $I2 reduces the substrate surface to about 80
While preheating the polycrystalline St layer to a temperature of about 0 C° Celsius, the main surface thereof is scanned by a linear infrared beam formed by the first infrared ray L′ to locally and sequentially melt the polycrystalline St layer, The 81 polycrystalline layers are sequentially turned into single crystals.

Note that the cover lI! formed on the polycrystalline S1 layer! teeth,
This is to prevent the polycrystalline 81 layer from adhering to the quartz glass flat plate 61 during melting. Also, when activating the ion-implanted layer, for example, by the method of the present invention,
For example, when using an infrared ray annealing furnace as shown in FIGS. 3(a) and 3(b), 1 is a rod-shaped infrared lamp, 2 is a reflector that has the function of forming parallel infrared rays, and 4
5 represents a stage, 5 represents a substrate to be processed, and 6 represents a quartz glass flat plate.

In the method of the present invention, as shown in the figure, a substrate 6 to be processed, which is made of a Si substrate having a diameter of about 5 inches, on which impurity ion implantation regions have been selectively formed, is placed with its main surface facing upward. A quartz glass flat plate 6 that fully covers the entire surface of the main surface and has a thickness of about 5 [■] is placed on the main surface, and in this state, By passing the stage 4 through the furnace at a predetermined speed, the surface portion of the escaping base material 5 is, for example, i o o o ('c).
The ion implantation region is activated by heating for about 10 seconds.

(2)) - Effects of the Invention In the first embodiment described above, when the substrate to be processed is locally heated, the substrate to be processed is sandwiched from both sides by the quartz glass plate with the entire surface under a desired pressure. Heating and cooling are performed. Therefore, the deformation (warpage) Fi of the substrate to be processed due to the infrared annealing treatment is significantly reduced, and can be suppressed to less than ±0.5 (#m) for a 5 [inch] silicon substrate, for example.

In the above-mentioned second embodiment, when the entire surface of the substrate to be processed was heated at a high temperature for a short time, the entire surface of the substrate to be processed was held down by the weight of the quartz glass flat plate placed on its main surface. Heating and cooling are done in this condition. Therefore, even in the infrared annealing process, the deformation (warpage) Fi of the substrate to be processed is reduced in the same way as in the first embodiment. 5 (x) The thickness of the silicon base is 0.5 [μm] or less in IK. As explained above, according to the present invention, the deformation of the substrate to be processed due to infrared annealing can be kept extremely small. Therefore, the present invention is effective in improving the manufacturing yield and performance of semiconductor devices, particularly SOIS structure semiconductor devices, and highly integrated semiconductor devices in which functional regions are often formed by ion implantation.

[Brief explanation of the drawing]

Fig. 1 is a schematic horizontal cross-sectional view of a conventional infrared radiant annealing furnace, and Fig. 2 is a schematic horizontal cross-sectional view of an infrared #Is radiant annealing furnace used in an embodiment of the present invention (A) and the A-A' arrow view. A vertical cross-sectional schematic diagram (b), FIG. 3 is a vertical cross-sectional schematic diagram (a) of an infrared radiation annealing furnace used in another embodiment, and A-A'
FIG. In the figure, %L 1mg lb is a rod-shaped infrared rung,
L 2ae 2bFi reflecting mirror, 3 is a semiconductor substrate, 4 is a stage, 5#-i substrate to be processed, 6.6mg 6b is a quartz glass plate, 7#'i pressurizing means, '8 is a supporter [9, L is Parallel infrared rays perpendicular to the irradiated surface, L indicates infrared rays focused on the normal scanning surface.

Claims (1)

[Claims] When performing high-temperature, short-time annealing treatment including local annealing on a flat substrate to be treated using a light radiation annealing furnace,
A photo-annealing method in which a flat plate made of a material that transmits light is pressed onto the entire surface of the substrate to be treated before annealing is performed.