JPS62263646A - Inspecting device for wafer - Google Patents

Abstract

PURPOSE:To prevent the interposition of a man as a dust source by automatically conducting the various inspection of a wafer after the completion of development in a lithographic process perfectly with high accuracy. CONSTITUTION:A wafer 1 after resist development is completed is carried as it is left as it is housed in a wafer cassette while being fed to a wafer holding section 2 by a wafer supply section 3. The wafer holding section 2 aligns the directions of rotation of the wafers 1, and a film-thickness inspection section 4 inspects the resist-film thickness of the wafers 1 extending over the whole surfaces of the wafers 1. A first surface inspection section 5 inspects the presence of foreign matters and flaws, a second surface inspection section 6 inspects a defective resist pattern, and a third surface inspection section 7 measures the displacement of alignment of a mask pattern and the width of a pattern line with submicron accuracy. A wafer discharge section 10 houses wafers 1 decided to be nondefectives into a nondefective housing cassette, and houses wafers 1 decided to be defectives into a defective cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a wafer inspection device that automatically performs various inspections on a semiconductor wafer on which a resist pattern is formed through a resist process.

(Prior art) Generally, integrated circuits such as ICs and LSIs are made of Si (
After forming a predetermined resist pattern on a silicon (silicon) wafer using a resist film, a portion is processed using an etching process, and impurities are introduced to form a pn junction.
Alternatively, it is manufactured by forming electrodes and wiring. What microfabrication is required in each of these processes?

This is done using lithography technology.

This phosphorography process consists of a resist process in which a mask pattern is transferred to a photoresist, and an etching process in which the underlying film is processed (etched) using the resist pattern and the resist is removed. By the way, the above-mentioned resist process includes a resist coating process in which a photoresist is applied by a resist coating device, and a soft baking process in which the photoresist is held in a baking oven for a certain period of time.

There is an exposure process in which a photomask is set by a mask alignment device and exposed by an exposure device, a development process in which the wafer that has undergone the exposure process is developed in a development device, and a test is carried out after this development process to check for insufficient development or unevenness. It consists of an inspection process.

By the way, the above-mentioned inspection process is currently performed by visual inspection, which is considered to be the most reliable method. However, in recent years, automation of semiconductor manufacturing has progressed, and automation of the inspection after the development process is required. In addition, as the degree of integration of semiconductor devices increases, there is a growing demand for eliminating inspectors as a source of dust.

(Problems to be Solved by the Invention) The present invention has been made in consideration of the desire for automation of post-development inspection in the phosphorography process, and an object of the present invention is to provide a wafer inspection device capable of completely automating the above-mentioned inspection. With the goal.

[Structure of the invention]

(Means and effects for solving the problem) A wafer supply unit that supplies a wafer with a resist pattern adhered to it, a wafer holding unit that positions and holds the wafer, and a film that inspects the resist film thickness of the wafer. It consists of a thickness inspection section, a surface inspection section that inspects the surface of the resist pattern on the wafer, a system control section that determines the quality of the wafer, and a wafer discharge section that selectively discards and discharges the wafer according to its quality.
The wafer inspection after development is completely automated.

(Example) An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the configuration of a wafer inspection apparatus of this embodiment. This equipment is used to process wafers (]) after resist development is completed.
a wafer supply section (3) that transports the wafers stored in a wafer cassette (not shown) and supplies them to a wafer holding section (2) (described later); and a wafer (1) supplied from the wafer supply section (3)K. A wafer holder (2) on which the wafer (1) is placed and uses an orientation flat to align the rotational direction of the wafer (1), and a resist film thickness of the wafer (1) held by this wafer holder (2). Wafer (
The film thickness inspection section (4) that inspects the entire surface of 1) and the surface of the pseudo-parallel wafer (1) that is selectively irradiated with the resist pattern are inspected for foreign matter and scratches [caused by scattering]. The presence or absence of these foreign objects and scratches is detected based on light on the wafer (
A first surface inspection unit (5) that inspects the entire surface of the wafer (1) and a resist pattern of the wafer (1) based on the intensity distribution of scattered light at the irradiation position of pseudo-parallel light selectively irradiated with respect to the example resist pattern. A second surface inspection section (6) that inspects defects and the mask pattern misalignment and pattern line width at multiple preset locations on the wafer (1) are determined to submicron levels by determining the edge position and distance of each pattern. 3rd yi + tree*s that determines 6 + li with precision
act7u-6,ノs4'i'-:'j4H9)Xl!
;lfim:s';41jl and the first to third surface inspection sections (5), (6), (7) 1 to 3rd surface inspection unit (5), (6), system control unit (9) that determines the quality of the wafer (1) based on the force inspection results;
) The wafer (1) determined to be a good product by K is stored in the good product storage cassette, and the wafer (1) determined to be a defective product
a wafer ejection unit (10) for storing the wafer into a defective product cassette;
System control unit (9) K is electrically connected to the transfer control unit (11
). However, the wafer holding part (2
) is a stage (Xa) that attaches and detaches the wafer (1).

This stage consists of an alignment section (not shown) that positions the wafer (1) in the oral direction based on the orientation flat of the wafer (1) placed one above it. The main body is an air cylinder that presses the wafer (1) against the reference pin.
), an image processing unit side that calculates the resist film thickness of the wafer (1) based on the imaging signal SA from the camera (13) using interference fringes generated due to the difference in film thickness, and
) is attached to the stage α and positions it so that the entire surface can be inspected (not shown).
It consists of Furthermore, the first to f83 surface inspection sections (5), (6), and (7) each have a wafer (1
) cameras (151, (16), αη) and imaging signals SB from these cameras (151, α0.(1η),
The image processing unit performs the above-mentioned predetermined surface treatment on the wafer (1) based on 8C and SD, and the stage on which the wafer (1) is adsorbed (1z can be held and inspected over the entire surface). X-Y table (
(not shown) and an illumination means (not shown) that irradiates the wafer (1) with parallel light. Here, the third surface inspection object (7) is.

Because the optical magnification is high, the automatic focus mechanism (I21) is the camera ση.
attached to.

The operation of the wafer inspection apparatus having the above configuration will now be described.

First, at the same time as the start of the inspection, when the system control section (9) outputs a control signal SM to the transfer control section (LD), the transfer control section (II) sends a control signal S to the wafer supply section (3).
N is output. Then, the wafer supply unit (3) starts and transfers the wafer (1) from the cassette to the wafer holding unit (2).
(Fig. 2, step (Sl)). Next, in the wafer holding section (2), the wafer (1) is aligned and attracted based on the orientation flat based on the control signal SO output from the transfer control section (11).

Next, a stage (one is
The wafer is transferred to the film thickness inspection section (4) by a control signal SQ output from the transfer control section (11) to the wafer transfer section (8). In the film thickness inspection section (4), the camera (131) outputs an imaging signal SA regarding the entire surface of the wafer (1) to the image processing section I while being positioned using the X-Y table. In the processing unit α4)K, the resist film thickness is calculated based on the shape of interference fringes caused by the difference in the resist film thickness, and an inspection signal SKI indicating film thickness data is output to the system control unit (9) (Fig. 2). .

step (82)). Then, once the film thickness inspection is completed,
As before, the stage (L2) is transported to the first surface inspection section (5). Then, in the same manner as the film thickness inspection section (4), the imaging signal SB is output from the camera (unhulled rice) to the image processing section (19). ) On the entire surface, scattered light generating sites corresponding to scratches, foreign objects, etc. are detected by the threshold method, and an inspection signal SK2 indicating the detection result is output to the system control unit (9) (Fig. 2, step (S3)). .Do the same below.

From the second surface inspection section (6), 3 is sent to the inspection signal 8 indicating the detection result regarding pattern shape defects over a wide area of the wafer (1), and then from the third surface inspection section (7),
An inspection signal SK4 indicating the misalignment of the mask pattern and the quality of the pattern line width is output to the system control unit (9) (FIG. 2, steps (S4), (35)>'.

Thus, the test signal SK1. SK2. SK3. S.K.
4 is input, and the system control unit (9) comprehensively judges these inspection results and finally determines whether the wafer (1) is a good product or a defective product (see step (FIG. 2)). S6)
”).Next, based on the determination result in the system control unit (9), from υ to the transfer control unit, the weno/discharge unit ([
A control signal ST is output to 1), and if the corresponding Weno (1) is a good product, 1-) Own A1 place Tsumugi + Fu-kLτ Give up! r When the factory calms down, store it in the defective product storage cassette (Fig. 2).

step (87)). The above operations are performed in the wafer supply section (3).
) is then performed on each wafer supplied by ilJ.

As described above, the wafer inspection apparatus of this embodiment is as follows.

Various inspections of a wafer after development in a lithography process can be performed completely automatically and with high precision. In particular, since there is no human intervention, a high degree of cleanliness can be maintained, making it suitable for manufacturing VLSIs and the like.

Note that the inspection items in Example 1' may be increased or decreased as desired. For example, the pattern shape inspection in the pattern second surface inspection section (6) may be omitted.

Furthermore, first to third surface inspection parts (5), (6),
The inspection in (7) may be performed simultaneously in one surface inspection section. Furthermore, the film thickness inspection department (4
) and first to third surface inspection sections (5), (6),
The order of (7) may be set arbitrarily.

〔Effect of the invention〕

The wafer inspection apparatus of the present invention can perform various inspections of the wafer after development in the phosphorography process completely automatically and with high precision. Therefore, there is no need for human intervention as a source of dust, making it extremely suitable for manufacturing highly integrated semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of wafer inspection equipment according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation. (1): Wafer, f2): Wafer holder. (3): Wafer supply section (4): & Thickness inspection section. (5): First surface inspection section; (6): Second surface inspection section. (7): Third surface inspection section, (9) Niji system control section, α0): Wafer discharge section. Agent Patent Attorney Noriyuki Chika Yudo Kikuo Takehana Figure 2

Claims (2)

[Claims] (1) A wafer supply section that supplies a wafer with a resist pattern attached, a wafer holding section that holds and positions the wafer supplied from this wafer supply section, and a resist on the wafer held by this wafer holding section. a film thickness inspection section that inspects the film thickness; a surface inspection section that inspects the surface of the resist pattern adhered to the wafer held in the wafer holding section; and inspections in the film thickness inspection section and the surface inspection section. A wafer inspection apparatus comprising: a control section that classifies the wafers into good and defective wafers based on the results and stores the wafers in a wafer storage section. (2) The surface inspection section includes a first surface inspection section that inspects the wafer for scratches and foreign matter, a second surface inspection section that inspects the resist pattern shape defects attached to the wafer, and a second surface inspection section that inspects the resist pattern attached to the wafer. 2. The wafer inspection apparatus according to claim 1, further comprising a third surface inspection section for inspecting mask misalignment of a resist pattern and line width of the pattern.