A nanometer process transistor total dose radiation effect on-line testing method

Abstract

The application relates to a kind of nanometer process transistor total dose radiation effect online testing methods, belong to the technical field of semiconductor device radiation resistance performance test, including the steps of pre-irradiation transfer characteristic curve test, pre-irradiation threshold voltage extraction, irradiation bias condition determination, online irradiation test, the extraction of the relationship between drain current and threshold voltage, online test data processing.The application can obtain device threshold voltage information by only carrying out current test of one bias voltage, and then realizes high sampling rate test of nanometer process transistor.The application solves the problems of less radiation damage information and inability to obtain continuous change of parameters with irradiation in the test of nanometer process transistor total dose radiation effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of testing the anti-radiation performance of semiconductor devices, and particularly relates to an on-line testing method for total dose radiation effects of nanometer process transistors. BACKGROUND

[0002] Semiconductor devices working in space radiation environment will be radiated by high-energy particles and rays, thereby causing the degradation of device performance and even the failure of functions. Therefore, the anti-radiation capability of semiconductor devices applied in space radiation environment must be evaluated to ensure the service life and reliability of satellite electronic systems. The total dose radiation effect is a permanent damage caused by the ionization of protons and electrons in the space radiation environment. The electrons and holes generated by the ionization of protons and electrons in the insulating layer of the device form trap charges such as oxide charges and interface states through the processes of recombination, separation, transport and capture, thereby causing the degradation of the electrical performance of the device. The total dose radiation effect is a main radiation effect problem faced by long-life satellites.

[0003] The miniaturization and high performance requirements of satellites have caused more and more nanometer process integrated circuits to be applied in satellite electronic systems. However, nanometer process devices such as fin field effect transistors and fully depleted silicon-on-insulator transistors adopt new structures such as three-dimensional channels, thereby causing them to face more complex total dose radiation effect problems. The radiation damage of nanometer process transistors is difficult to predict, and there are many factors affecting the radiation damage of devices, thereby bringing severe challenges to the evaluation of the anti-total dose radiation capability of devices.

[0004] At present, the evaluation test of the total dose effect of nanometer process devices usually adopts an off-line testing method. The devices are removed from the irradiation source for parameter testing at several irradiation dose points. The off-line testing can only test the radiation damage information of nanometer devices at individual dose points, and it is difficult to obtain the continuous change process of the key parameters of the device with irradiation, and then to perform a comprehensive analysis of the radiation damage mechanism. SUMMARY

[0005] In order to overcome the insufficient amount of radiation damage information and the inability to obtain the continuous change of parameters with irradiation in the test of the total dose radiation effect of nanometer process transistors, the application provides an on-line testing method for the total dose radiation effect of nanometer process transistors.

[0006] The technical solution adopted by the application to solve the technical problems is as follows:

[0007] An on-line testing method for the total dose radiation effect of nanometer process transistors, comprising the following steps:

[0008] Step 1, testing the transfer characteristic curve before irradiation

[0009] Before the start of irradiation, the transfer characteristic before irradiation is tested, and the transfer characteristic curve of the nanometer process transistor is drawn.

[0010] Step 2, threshold voltage V before irradiation th Extraction

[0011] Threshold voltage V at the gate end before irradiation th , that is, threshold voltage V th .

[0012] The transfer characteristic curve obtained in step 1 is fitted in combination with the gate structure of the nanometer process transistor to obtain the drain-drain end current I D and the corresponding relationship with the channel width W and the channel length L.

[0013] I D = 10 -7 W / L

[0014] In the above formula, I D is in amperes, the drain current I D corresponds to the gate scanning voltage V GS , that is, the threshold voltage V th of the nanometer process transistor.

[0015] Step 3, determination of irradiation bias condition

[0016] The irradiation bias condition of the nanometer process transistor is that the drain bias voltage is the same as the bias voltage applied in step 1, that is, V DS , and the gate bias voltage V GS is V GS = V th ± 100 mV. The source end and the substrate are grounded.

[0017] Before the start of the irradiation test, the bias condition is applied to the nanometer process transistor.

[0018] Step 4, online irradiation test

[0019] Under the irradiation bias condition determined in step 3, the nanometer process transistor is continuously irradiated, and the drain current I D(on_line) is tested in real time, and the curve of the drain current I D(on_line) with time is drawn.

[0020] Step 5, extraction of the relationship between the drain current I D(on_line) and the threshold voltage V th

[0021] During the online irradiation of step 4, the irradiation time point is selected, steps 1 to 3 are repeated, the drain current I D(on_line) and the threshold voltage V th value corresponding to the irradiation time point are obtained, and the threshold voltage V th and the drain current I D(on_line) dependence equation are fitted. ​

[0022] Step 6, online test data processing

[0023] The leakage current I D(on_line) The test data is substituted into the threshold voltage V th The leakage current I D(on_line) The threshold voltage V th .

[0024] The above-mentioned online testing method for total dose radiation effects of nanometer process transistors, the step 1 irradiation before transfer characteristic curve test, further comprises:

[0025] A bias voltage V DS , that is, the drain bias voltage V DS , is applied to the gate end GS , that is, the gate scanning voltage V GS , is applied to the scanning process D , that is, the drain current I D . Get the change rule of the drain current I D with the gate scanning voltage V GS , draw the transfer characteristic curve of the nanometer process transistor according to the change rule, that is, the transfer characteristic curve of the nanometer process transistor.

[0026] The above-mentioned online testing method for total dose radiation effects of nanometer process transistors, the step 1 irradiation before transfer characteristic curve test, further comprises: DS The drain bias voltage V GS is 0.1V, and the gate scanning voltage V DS ranges from 0 to 0.8V.

[0027] The above-mentioned online testing method for total dose radiation effects of nanometer process transistors, the step 3 irradiation bias condition determination, V DS =0.1V, V GS =250mV.

[0028] The above-mentioned online testing method for total dose radiation effects of nanometer process transistors, the step 4 online irradiation test, real-time test of the drain current I D(on_line) , the time interval between two consecutive tests is less than or equal to 200 milliseconds.

[0029] The above-mentioned online testing method for total dose radiation effects of nanometer process transistors, the step 5 leakage current I D(on_line) and threshold voltage V th relationship extraction, further comprises:

[0030] In the step 4 online irradiation process, select the irradiation time point, after reaching the corresponding irradiation time, stop irradiation and record the drain current ID(on_line) Then, the transfer characteristic curve test is carried out according to the test condition of step 1, and the V th Then, the bias condition of step 3 is restored to continue the online irradiation.

[0031] The above-mentioned total dose radiation effect online test method of nanometer process transistor, the step 5 leakage current I D(on_line) and the threshold voltage V th In the relationship extraction, 3-10 irradiation time points are selected.

[0032] The above-mentioned total dose radiation effect online test method of nanometer process transistor, the step 5 leakage current I D(on_line) and the threshold voltage V th In the relationship extraction, 1000 seconds, 2000 seconds, 3000 seconds irradiation time are selected to carry out the interruption test of the transfer characteristic curve. The leakage current I D(on_line) and the threshold voltage V th relationship diagram, and the fitting equation is:

[0033]

[0034] The beneficial effects of the present application are:

[0035] A total dose radiation effect online test method of nanometer process transistor, according to the parameter degradation mechanism of nanometer process transistor caused by radiation, a rapid test method of device threshold voltage is proposed, only one bias voltage current test can obtain the device threshold voltage information, the nanometer process transistor parameter test time is reduced to millisecond time scale, and high sampling rate test of nanometer process transistor is realized. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is the transfer characteristic curve test result of 22 nanometer process transistor before irradiation;

[0037] Figure 2 It is the relationship between the leakage current of 22 nanometer process transistor and the irradiation time;

[0038] Figure 3 It is the dependence relationship between the leakage current of 22 nanometer process transistor and the threshold voltage and the fitting equation curve; the points in the figure are the test results, and the line is the fitting equation curve;

[0039] Figure 4 It is the threshold voltage and irradiation time relationship diagram of 22 nanometer process transistor. DETAILED DESCRIPTION

[0040] Embodiment 1

[0041] A method for online testing of total dose radiation effects of nano-process transistors comprises the following steps:

[0042] Step 1: Transfer characteristic curve test before irradiation

[0043] Before irradiation begins, the transfer characteristic curve test is performed on the nano-process transistor. The nano-process transistor includes four terminals: the gate terminal (G terminal), the drain terminal (D terminal), the source terminal (S terminal), and the substrate terminal (B terminal). A fixed drain bias voltage V greater than or equal to 0.05V is applied to the drain terminal. DS , apply gate scan voltage V at the gate end GS , the scanning voltage range is 0V to the rated working voltage V dd , in V GS During the scanning process, the leakage current is tested, that is, the leakage current I D .

[0044] In this embodiment, a transfer characteristic curve test is performed on a 22nm process transistor. The rated operating voltage of the device is 0.8V, where V DS＝ 0.1V, V GS Scan in the range of 0-0.8V, the test results are as follows Figure 1 shown.

[0045] Step 2: Threshold voltage extraction before irradiation

[0046] In the transfer characteristic curve tested in step 1, I D =10 -7 *W / L (amperes) corresponds to V GS That is the threshold voltage V of the nanometer process transistor th , where W is the channel width and L is the channel length.

[0047] In this embodiment, the W of the transistor under test is 80nm, L is 20nm, and Figure 1 Extracting the transistor's V th =267mV.

[0048] Step 3: Determine the irradiation bias condition

[0049] Before the irradiation test begins, bias conditions are applied to the nano-process transistor, where the drain terminal is applied with the same bias voltage V as in step 1. DS , gate bias voltage V GS In V th ±100mV range, V th To extract the value in step 2, the S and B terminals are grounded.

[0050] The irradiation bias condition of the transistor under test in this embodiment is: V DS =0.1V, V GS= 250 mV, S terminal, B terminal grounded.

[0051] Step 4, in-line irradiation test

[0052] During irradiation, the nano-process transistor maintains the bias condition in step 3, and the drain current I is continuously tested D(on_line) , and the interval between two consecutive tests is less than or equal to 200 milliseconds.

[0053] In this embodiment, the interval between two consecutive tests of the transistor being tested is 100 milliseconds, and I D(on_line) The relationship with time is shown in Figure 2 .

[0054] Step 5, I D(on_line) and V th relationship extraction

[0055] During the in-line irradiation in step 4, 3-10 irradiation times are selected, after reaching the corresponding irradiation time, the irradiation is stopped and the I D(on_line) value at this time is recorded, then the transfer characteristic curve test is carried out according to the test conditions of step 1, and V th is extracted according to the method of step 2, then the bias condition of step 3 is restored to continue the in-line irradiation. According to the I D(on_line) and V th values obtained by interrupting the test, the V th and I D(on_line) dependence equation is fitted.

[0056] In this embodiment, 1000 seconds, 2000 seconds, and 3000 seconds of irradiation time are selected for interrupting the test of the transfer characteristic curve. Figure 3 The I D(on_line) and V th relationship diagram is shown, and the dependence equation of the two is fitted, and the fitted equation is as follows:

[0057]

[0058] Step 6, in-line test data processing

[0059] The I D(on_line) test data corresponding to different irradiation times is brought into the V th and I D(on_line) dependence equation obtained in step 3, to obtain the V th of the nano-process transistor corresponding to different irradiation times.

[0060] Figure 4 The V th and irradiation time relationship diagram of the 22 nm process transistor obtained in this embodiment is shown.

Claims

1. A method for on-line testing of total dose radiation effects in nanometer technology transistors, characterized in that Comprising the following steps: Step 1, pre-irradiation transfer characteristic curve test: Before irradiation, test the pre-irradiation transfer characteristic, draw the transfer characteristic curve of the nanometer process transistor; Step 2, pre-irradiation threshold voltage V th Extraction: extracting the leakage current I from the transfer characteristic curve of the nanometer process transistor D corresponding to the gate scanning voltage V GS , obtaining the threshold voltage V of the nanometer process transistor th ; Step 3, determine the irradiation bias condition: Before the irradiation test starts, the irradiation bias condition applied to the nanometer process transistor is determined; the irradiation bias condition is: drain bias voltage V DS greater than or equal to 0.05V, gate scanning voltage V GS The value is: V GS = V th ±100mV; The source end and the substrate are grounded; Step 4, online irradiation test: The nanometer process transistors were subjected to continuous online irradiation under the irradiation bias conditions applied in Step 3, and the drain current I was tested in real time D(on_line) The drain current I D(on_line) versus time curve was plotted; Step 5, leakage current I D(on_line) with threshold voltage V th Relationship extraction: In the online irradiation process of step 4, at least three different irradiation times are selected, steps 1 to 3 are repeated, and the leakage current I corresponding to different irradiation times is obtained D(on_line) with the threshold voltage V th value, the threshold voltage V th with the leakage current I D(on_line) dependent equation; Step 6, online test data processing: The leakage current I corresponding to different irradiation times is measured D(on_line) The test data is substituted into the threshold voltage V obtained in step 5 th The leakage current I corresponding to different irradiation times is measured D(on_line) The threshold voltage V corresponding to different irradiation times is obtained according to the dependence equation th .

2. The nanometer process transistor total ionizing dose radiation effect on-line test method of claim 1, wherein, The leakage current I D is calculated as follows: D = 10 -7 W / L, where I D is in amperes, W is the channel width, and L is the channel length.

3. The nanometer process transistor total ionizing dose radiation effects on-line test method according to claim 1 or 2, wherein, The step 1 pre-irradiation transfer characteristic curve test further comprises: A drain bias voltage V is applied to the drain end of the nanometer process transistor DS A gate scanning voltage V is applied to the gate end GS During scanning, the drain current I is tested D The drain current I is obtained D The change rule of the drain current I with the gate scanning voltage V GS The transfer characteristic curve of the nanometer process transistor is drawn according to the change rule.

4. The nanometer process transistor total ionizing dose radiation effect on-line test method of claim 3, wherein, The pre-irradiation transfer characteristics curve test was performed on 22 nm process transistors, the drain bias voltage V DS was 0.1 V, and the gate scanning voltage V GS was in the range of 0-0.8 V.

5. The nanometer process transistor total ionizing dose radiation effects on-line test method of claim 4, wherein, In the step 3 irradiation bias condition determination, the drain bias voltage V DS = 0.1 V, the gate scanning voltage V GS = 250 mV.

6. The nanometer process transistor total ionizing dose radiation effect on-line test method of claim 1, wherein, The step 4 is an on-line irradiation test, real-time test of leakage current I D(on_line) The time interval between two consecutive tests is less than or equal to 200 milliseconds.

7. The nanometer process transistor total ionizing dose radiation effect on-line test method of claim 1, wherein, The step 5 leakage current I D(on_line) with the threshold voltage V th relationship extraction, further comprising: During the on-line irradiation of step 4, the irradiation time is selected, and after the corresponding irradiation time is reached, the irradiation is stopped and the leakage current I at this time is recorded D(on_line) Then, the transfer characteristic curve test is performed according to the test conditions of step 1, and the threshold voltage V is extracted according to the method of step 2 th Then, the bias conditions of step 3 are resumed to continue the on-line irradiation.

8. The nanometer process transistor total ionizing dose radiation effects on-line test method of claim 1 or 7, wherein, The step 5 leakage current I D(on_line) with the threshold voltage V th In the relationship extraction, 3-10 irradiation times are selected.

9. The nanometer process transistor total ionizing dose radiation effect on-line test method of claim 5, wherein, The step 5 leakage current I D(on_line) with threshold voltage V th In the relationship extraction, 1000 seconds, 2000 seconds, 3000 seconds irradiation time, the transfer characteristic curve of the interruption test; the leakage current I D(on_line) with threshold voltage V th The relationship diagram, the fitting equation is:

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