Active matrix using hybrid integrated circuit and bipolar transistor

1. A pixel circuit for an active matrix display, comprising:

a junction field effect transistor (JFET);

a bipolar junction coupled to the JFET to receive data through the JFET, when enabled, at a base of the bipolar junction, the JFET and the bipolar junction including a crystalline channel material; and

an organic light emitting diode (OLED) being connected on one side between one of an emitter and a collector of the bipolar junction and, on the other side, between one of supply voltage and ground,

wherein the circuit includes a non-direct programming circuit and the OLED includes a bottom-emission device.

2. The circuit as recited in claim 1 , wherein the JFET includes a p-type channel material and the bipolar junction includes a n-p-n junction such that current through the OLED includes: I OLED ≈β(V data −V BE −V OLED )/R ON where β is a ratio of collector current to base current, V data is a data voltage, V BE is a base-emitter voltage, V OLED is a voltage across the OLED and R ON is an on resistance of the JFET.

3. The circuit as recited in claim 1 , further comprising a storage capacitor coupled between a base and a collector of the bipolar junction.

4. The circuit as recited in claim 1 , being formed on a hybrid integrated circuit device, comprising:

a semiconductor-on-insulator substrate having a base substrate, a semiconductor layer and a dielectric layer disposed therebetween, the base substrate being reduced in thickness;

first devices formed in the semiconductor layer, the first devices being connected to first metallizations on a first side of the dielectric layer;

second devices including the pixel circuit formed in the base substrate, the second devices being connected to second metallizations formed on a second side of the dielectric layer opposite the first side; and

at least one through via connection configured to connect the first metallizations to the second metallizations through the dielectric layer.

5. The circuit as recited in claim 4 , wherein the first devices include complementary metal oxide semiconductor devices.

6. The circuit as recited in claim 4 , wherein the base substrate includes a single crystal or multi-crystal material, and the second devices include transistors employing the base substrate as a transistor body.

7. The circuit as recited in claim 4 , wherein at least one of the first devices and the second devices are included in an active matrix display.

8. The circuit as recited in claim 4 , wherein the base substrate layer includes doped regions formed therein and the doped regions connect to the at least one through via connection to connect the first metallizations to the second metallizations.

9. The circuit as recited in claim 4 , wherein the first metallizations are connected to the second metallizations by metal-to-metal contact including the at least one through via connection.

10. The circuit as recited in claim 4 , wherein the second devices include bipolar transistors formed in a single crystal or multi-crystal base material and having doped regions formed from amorphous silicon patterned on the base material.

11. The circuit as recited in claim 10 , wherein the amorphous silicon includes hydrogenated silicon patterned on the base material, wherein the hydrogenated Si includes 5-40 atomic percent hydrogen.

12. The circuit as recited in claim 1 , wherein a drain or source of the JFET is connected to the base of the bipolar junction, and the emitter of the bipolar junction is connected to the anode of the OLED.

13. A pixel circuit for an active matrix display, comprising:

first devices formed in a semiconductor layer of a semiconductor-on-insulator substrate, the first devices being connected to first metallizations on a first side of a dielectric layer of the semiconductor-on-insulator substrate;

second devices including the pixel circuit formed in a base substrate of the semiconductor-on-insulator substrate, the second devices being connected to second metallizations formed on a second side of the dielectric layer opposite the first side; and

at least one through via connection configured to connect the first metallizations to the second metallizations through the dielectric layer;

the first and second devices including different device types, the device types including at least one of a junction field effect transistor (JFET), complementary metal oxide field effect transistors (CMOS FETs), a thin film transistor (TFT) or a bipolar junction, the first and second devices being coupled by the at least one through via connection.

14. A pixel circuit for an active matrix display, comprising:

a junction field effect transistor (JFET);

a bipolar junction coupled to the JFET to receive data through the JFET, when enabled, at a base of the bipolar junction, the JFET and the bipolar junction including a crystalline channel material; and

an organic light emitting diode (OLED) being connected on one side between one of an emitter and a collector of the bipolar junction and, on the other side, between one of supply voltage and ground,

wherein the circuit includes a direct programming circuit and the OLED includes a top-emission device.

15. The circuit as recited in claim 14 , wherein the JFET includes a p-type channel material and the bipolar junction includes n-p-n junction such that current through the OLED includes: I OLED ≈β(V data −V BE )/R ON where β is a ratio of collector current to base current, V data is a data voltage, V BE is a base-emitter voltage, and R ON is an on resistance of the JFET.

16. The circuit as recited in claim 14 , further comprising a storage capacitor coupled between a base of the bipolar junction and a ground.

17. The circuit as recited in claim 14 , wherein a drain or source of the p-channel JFET is connected to the base of the bipolar junction, and the collector of the bipolar junction is connected to the cathode of the OLED.