Share-Based Compensation Plans

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

For the years ended December 31, 2023, 2022 and 2021, we recognized share-based compensation of $8.3 million, $13.6 million and $11.0 million, respectively, primarily in selling, general and administrative expenses. The amount of compensation expense to be recognized is adjusted for an estimated forfeiture rate which is based on historical data. The corresponding deferred income tax benefits are $0.7 million, $1.7 million and $1.4 million for 2023, 2022 and 2021, respectively.

Equity Incentive Plans

Second Amended and Restated 2007 Equity Incentive Plan. The Second Amended and Restated 2007 Equity Incentive Plan (as amended, the “2007 Plan”) provided for the grant of the following types of incentive awards: (i) stock options; (ii) restricted stock; (iii) restricted stock units; (iv) stock appreciation rights; (v) performance units and performance shares; and (vi) other stock or cash awards. Those eligible for awards included employees, directors and consultants who provide services to Amkor and its subsidiaries. There were originally 17.0 million shares of our common stock reserved for issuance under the 2007 Plan. No awards have been or will be granted under the 2007 Plan after the effective date of the 2021 Plan (as defined below), but all outstanding awards under the 2007 Plan will continue in full force and effect, subject to their original terms.

2021 Equity Incentive Plan. On May 18, 2021, at our 2021 Annual Meeting of Stockholders (the “2021 Annual Meeting”), our stockholders approved the Amkor Technology, Inc. 2021 Equity Incentive Plan (as amended, the “2021 Plan”) to replace the 2007 Plan. The 2021 Plan provides for the grant of the following types of incentive awards: (i) stock options; (ii) restricted stock; (iii) restricted stock units; (iv) stock appreciation rights; (v) performance units and performance shares; and (vi) other stock or cash awards. Those eligible for awards include employees, directors and consultants who provide services to Amkor and its subsidiaries. The number of shares authorized and available for issuance under the 2021 Plan is 23,100,000 shares, reduced for certain awards granted under the 2007 Plan after December 31, 2020, but before May 18, 2021. There were originally 22.8 million shares of our common stock reserved for issuance under the 2021 Plan, and at December 31, 2023, there were 20.6 million shares available for grant under the 2021 Plan.

Stock options

Stock options are generally granted with an exercise price equal to the market price of the stock at the date of grant. Substantially all of the options granted are exercisable pursuant to a one to four year vesting schedule, and the term of the options granted is no longer than ten years. Upon option exercise, we may issue new shares of common or treasury stock.

In order to calculate the fair value of stock options at the date of grant, we use the Black-Scholes option pricing model. Expected volatilities are based on historical performance of our stock. We also use historical data to estimate the timing and amount of option exercises and forfeitures within the valuation model. The expected term of the options is based on evaluations of historical and expected future employee exercise behavior and represents the period of time that options granted are expected to be outstanding. The risk-free interest rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The dividend yield is based on the annualized declared quarterly dividend rate divided by our closing stock price at the date of the grant.

The following table summarizes our stock option activity for the year ended December 31, 2023:


	Number of Shares (In thousands)	Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In thousands)
Outstanding at December 31, 2022	2,376	$	10.54
Granted	—	—
Exercised	(345)	10.31
Forfeited or expired	—	—
Outstanding at December 31, 2023	2,031	$	10.58	4.98 years	$	46,068
Fully vested at December 31, 2023 and expected to vest thereafter	2,029	$	10.58	4.98 years	$	46,029
Exercisable at December 31, 2023	1,973	$	10.51	4.93 years	$	44,903

Total unrecognized compensation expense from stock options was $0.3 million as of December 31, 2023, which is expected to be recognized over a weighted-average period of approximately 0.79 years beginning January 1, 2024. The total intrinsic value of options exercised during fiscal years 2023, 2022, and 2021 was $5.8 million, $8.0 million, and $17.7 million, respectively.

Restricted shares

Restricted shares granted to our non-employee directors vest on the earlier of the one year anniversary of the grant date or the date of the annual meeting of stockholders immediately following the grant date, subject to the recipient’s continued service as a director of Amkor on the applicable vesting date. Generally, other restricted shares vest ratably over three years, with 8.33% of the shares vesting in equal quarterly installments such that 100% of the shares will become vested on the third anniversary of the award, subject to the recipient’s continued employment with us on the applicable vesting date. In addition, provided that the restricted shares have not been forfeited earlier, under the terms and conditions of the applicable award agreements for certain grants, the restricted shares will vest upon the recipient’s death or disability, or upon a change in control of Amkor. The value of the restricted shares is determined based on the fair market value of the underlying shares on the date of the grant and is recognized ratably over the vesting period.

The following table summarizes our restricted share activity for the year ended December 31, 2023:


	Number of Shares (In thousands)	Weighted- average Grant Date Fair Value (Per Share)
Non-vested at December 31, 2022	109	$	15.38
Awards granted	—	—
Awards vested	(109)	15.38
Awards forfeited	—	—
Non-vested at December 31, 2023	—	$	—

For the year ended December 31, 2023, the total fair value of our vested restricted shares was $2.9 million, respectively.

Restricted stock units

From time to time, and pursuant to the 2021 Plan, we grant time-vested restricted stock units (“RSUs”) to our non-employee directors and certain employees and performance-vested restricted stock units (“PSUs”) to certain employees. RSUs generally vest in four equal installments over a four-year period such that 100% of the RSUs will become vested

on the fourth anniversary of the award, subject to the recipient’s continued employment with us on the applicable vesting dates. In some circumstances, we have granted RSUs subject to different vesting conditions, including RSUs that vest in full in a single installment. Provided that the RSUs have not been forfeited earlier, they will generally vest upon the recipient’s retirement, death or disability, or upon a change in control of Amkor, in accordance with the terms and conditions of the applicable award agreement. The value of the RSUs is determined based on the fair market value of the underlying shares on the date of the grant, reduced by the present value of dividends or dividend equivalent rights expected to be paid on our common stock prior to vesting, and is recognized ratably over the vesting period.

PSUs generally vest in one installment after a two-year period such that any earned PSUs will become vested within 90 days of the second anniversary of the award, subject to the recipient’s continued employment with us on the applicable vesting date. Generally for PSUs, the number of shares of our common stock to be received at vesting will range from 0% to 200% of the target grant amount based on Cumulative Basic EPS (as defined in the applicable award agreement) over a two-year performance measurement period. In some circumstances, we have granted PSUs subject to different vesting conditions, including PSUs that vest in full upon the achievement of performance goals other than Cumulative Basic EPS. Provided the PSUs have not been forfeited earlier, the PSUs will generally vest upon the recipient’s retirement, death or disability, or upon a change of control of Amkor, in accordance with the terms and conditions of the applicable award agreement. The value of the PSUs is initially determined based on the fair market value of the underlying shares on the date of the grant, reduced by the present value of dividends expected to be paid on our common stock prior to vesting, and is recognized over the vesting period.

The following table summarizes our RSU and PSU activity:


	Number of Shares (In thousands)	Weighted- average Grant Date Fair Value (Per Share)
Non-vested at December 31, 2020	—	$	—
Awards granted	295	22.48
Awards vested	—	—
Awards forfeited	(9)	22.58
Non-vested at December 31, 2021	286	22.48
Awards granted	531	22.29
Awards vested	(22)	22.23
Awards forfeited	(57)	22.63
Non-vested at December 31, 2022	738	22.34
Awards granted	1,049	26.72
Awards vested	(464)	22.19
Awards forfeited	(16)	25.24
Non-vested at December 31, 2023	1,307	$	25.87

Total unrecognized compensation expense from RSUs and PSUs was $12.1 million as of December 31, 2023, which is expected to be recognized over a weighted-average period of approximately 1.3 years beginning January 1, 2024.

For the years ended December 31, 2023 and 2022, the total fair value of our vested RSUs and PSUs were $11.6 million and $0.5 million, respectively.